<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Disease and can you explain it in depth? [/INST] A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that are associated with specific signs and symptoms. A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergies and autoimmune disorders.
In humans, disease is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person affected, or similar problems for those in contact with the person. In this broader sense, it sometimes includes injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts and for other purposes these may be considered distinguishable categories. Diseases can affect people not only physically, but also mentally, as contracting and living with a disease can alter the affected persons perspective on life.
Death due to disease is called death by natural causes. There are four main types of disease: infectious diseases, deficiency diseases, hereditary diseases (including both genetic diseases and non-genetic hereditary diseases), and physiological diseases. Diseases can also be classified in other ways, such as communicable versus non-communicable diseases. The deadliest diseases in humans are coronary artery disease (blood flow obstruction), followed by cerebrovascular disease and lower respiratory infections. In developed countries, the diseases that cause the most sickness overall are neuropsychiatric conditions, such as depression and anxiety.
The study of disease is called pathology, which includes the study of etiology, or cause.

Terminology
Concepts
In many cases, terms such as disease, disorder, morbidity, sickness and illness are used interchangeably; however, there are situations when specific terms are considered preferable.
Disease
The term disease broadly refers to any condition that impairs the normal functioning of the body. For this reason, diseases are associated with the dysfunction of the bodys normal homeostatic processes. Commonly, the term is used to refer specifically to infectious diseases, which are clinically evident diseases that result from the presence of pathogenic microbial agents, including viruses, bacteria, fungi, protozoa, multicellular organisms, and aberrant proteins known as prions. An infection or colonization that does not and will not produce clinically evident impairment of normal functioning, such as the presence of the normal bacteria and yeasts in the gut, or of a passenger virus, is not considered a disease. By contrast, an infection that is asymptomatic during its incubation period, but expected to produce symptoms later, is usually considered a disease. Non-infectious diseases are all other diseases, including most forms of cancer, heart disease, and genetic disease.
Acquired disease
An acquired disease is one that began at some point during ones lifetime, as opposed to disease that was already present at birth, which is congenital disease. Acquired sounds like it could mean "caught via contagion", but it simply means acquired sometime after birth. It also sounds like it could imply secondary disease, but acquired disease can be primary disease.
Acute disease
An acute disease is one of a short-term nature (acute); the term sometimes also connotes a fulminant nature
Chronic condition or chronic disease
A chronic disease is one that persists over time, often characterized as at least six months but may also include illnesses that are expected to last for the entirety of ones natural life.
Congenital disorder or congenital disease
A congenital disorder is one that is present at birth. It is often a genetic disease or disorder and can be inherited. It can also be the result of a vertically transmitted infection from the mother, such as HIV/AIDS.
Genetic disease
A genetic disorder or disease is caused by one or more genetic mutations. It is often inherited, but some mutations are random and de novo.
Hereditary or inherited disease
A hereditary disease is a type of genetic disease caused by genetic mutations that are hereditary (and can run in families)
Iatrogenic disease
An iatrogenic disease or condition is one that is caused by medical intervention, whether as a side effect of a treatment or as an inadvertent outcome.
Idiopathic disease
An idiopathic disease has an unknown cause or source. As medical science has advanced, many diseases with entirely unknown causes have had some aspects of their sources explained and therefore shed their idiopathic status. For example, when germs were discovered, it became known that they were a cause of infection, but particular germs and diseases had not been linked. In another example, it is known that autoimmunity is the cause of some forms of diabetes mellitus type 1, even though the particular molecular pathways by which it works are not yet understood. It is also common to know certain factors are associated with certain diseases; however, association and causality are two very different phenomena, as a third cause might be producing the disease, as well as an associated phenomenon.
Incurable disease
A disease that cannot be cured. Incurable diseases are not necessarily terminal diseases, and sometimes a diseases symptoms can be treated sufficiently for the disease to have little or no impact on quality of life.
Primary disease
A primary disease is a disease that is due to a root cause of illness, as opposed to secondary disease, which is a sequela, or complication that is caused by the primary disease. For example, a common cold is a primary disease, where rhinitis is a possible secondary disease, or sequela. A doctor must determine what primary disease, a cold or bacterial infection, is causing a patients secondary rhinitis when deciding whether or not to prescribe antibiotics.
Secondary disease
A secondary disease is a disease that is a sequela or complication of a prior, causal disease, which is referred to as the primary disease or simply the underlying cause (root cause). For example, a bacterial infection can be primary, wherein a healthy person is exposed to bacteria and becomes infected, or it can be secondary to a primary cause, that predisposes the body to infection. For example, a primary viral infection that weakens the immune system could lead to a secondary bacterial infection. Similarly, a primary burn that creates an open wound could provide an entry point for bacteria, and lead to a secondary bacterial infection.
Terminal disease
A terminal disease is one that is expected to have the inevitable result of death. Previously, AIDS was a terminal disease; it is now incurable, but can be managed indefinitely using medications.
Illness
The terms illness and sickness are both generally used as synonyms for disease; however, the term illness is occasionally used to refer specifically to the patients personal experience of his or her disease. In this model, it is possible for a person to have a disease without being ill (to have an objectively definable, but asymptomatic, medical condition, such as a subclinical infection, or to have a clinically apparent physical impairment but not feel sick or distressed by it), and to be ill without being diseased (such as when a person perceives a normal experience as a medical condition, or medicalizes a non-disease situation in his or her life – for example, a person who feels unwell as a result of embarrassment, and who interprets those feelings as sickness rather than normal emotions). Symptoms of illness are often not directly the result of infection, but a collection of evolved responses – sickness behavior by the body – that helps clear infection and promote recovery. Such aspects of illness can include lethargy, depression, loss of appetite, sleepiness, hyperalgesia, and inability to concentrate.
Disorder
A disorder is a functional abnormality or disturbance. Medical disorders can be categorized into mental disorders, physical disorders, genetic disorders, emotional and behavioral disorders, and functional disorders. The term disorder is often considered more value-neutral and less stigmatizing than the terms disease or illness, and therefore is preferred terminology in some circumstances. In mental health, the term mental disorder is used as a way of acknowledging the complex interaction of biological, social, and psychological factors in psychiatric conditions; however, the term disorder is also used in many other areas of medicine, primarily to identify physical disorders that are not caused by infectious organisms, such as metabolic disorders.
Medical condition or health condition
A medical condition or health condition is a broad concept that includes all diseases, lesions, disorders, or nonpathologic condition that normally receives medical treatment, such as pregnancy or childbirth. While the term medical condition generally includes mental illnesses, in some contexts the term is used specifically to denote any illness, injury, or disease except for mental illnesses. The Diagnostic and Statistical Manual of Mental Disorders (DSM), the widely used psychiatric manual that defines all mental disorders, uses the term general medical condition to refer to all diseases, illnesses, and injuries except for mental disorders. This usage is also commonly seen in the psychiatric literature. Some health insurance policies also define a medical condition as any illness, injury, or disease except for psychiatric illnesses.
As it is more value-neutral than terms like disease, the term medical condition is sometimes preferred by people with health issues that they do not consider deleterious. On the other hand, by emphasizing the medical nature of the condition, this term is sometimes rejected, such as by proponents of the autism rights movement.
The term medical condition is also a synonym for medical state, in which case it describes an individual patients current state from a medical standpoint. This usage appears in statements that describe a patient as being in critical condition, for example.
Morbidity
Morbidity (from Latin  morbidus sick, unhealthy) is a diseased state, disability, or poor health due to any cause. The term may refer to the existence of any form of disease, or to the degree that the health condition affects the patient. Among severely ill patients, the level of morbidity is often measured by ICU scoring systems. Comorbidity, or co-existing disease, is the simultaneous presence of two or more medical conditions, such as schizophrenia and substance abuse.
In epidemiology and actuarial science, the term morbidity (also morbidity rate or morbidity frequency) can refer to either the incidence rate, the prevalence of a disease or medical condition, or the percentage of people who experience a given condition within a given timeframe (e.g., 20% of people will get influenza in a year). This measure of sickness is contrasted with the mortality rate of a condition, which is the proportion of people dying during a given time interval. Morbidity rates are used in actuarial professions, such as health insurance, life insurance, and long-term care insurance, to determine the correct premiums to charge to customers. Morbidity rates help insurers predict the likelihood that an insured will contract or develop any number of specified diseases.
Pathosis or pathology
Pathosis (plural pathoses) is synonymous with disease. The word pathology also has this sense, in which it is commonly used by physicians in the medical literature, although some editors prefer to reserve pathology to its other senses. Sometimes a slight connotative shade causes preference for pathology or pathosis implying "some [as yet poorly analyzed] pathophysiologic process" rather than disease implying "a specific disease entity as defined by diagnostic criteria being already met". This is hard to quantify denotatively, but it explains why cognitive synonymy is not invariable.
Syndrome
A syndrome is the association of several signs and symptoms, or other characteristics that often occur together, regardless of whether the cause is known. Some syndromes such as Down syndrome are known to have only one cause (an extra chromosome at birth). Others such as Parkinsonian syndrome are known to have multiple possible causes. Acute coronary syndrome, for example, is not a single disease itself but is rather the manifestation of any of several diseases including myocardial infarction secondary to coronary artery disease. In yet other syndromes, however, the cause is unknown. A familiar syndrome name often remains in use even after an underlying cause has been found or when there are a number of different possible primary causes. Examples of the first-mentioned type are that Turner syndrome and DiGeorge syndrome are still often called by the "syndrome" name despite that they can also be viewed as disease entities and not solely as sets of signs and symptoms.
Predisease
Predisease is a subclinical or prodromal vanguard of a disease. Prediabetes and prehypertension are common examples. The nosology or epistemology of predisease is contentious, though, because there is seldom a bright line differentiating a legitimate concern for subclinical/prodromal/premonitory status (on one hand) and conflict of interest–driven disease mongering or medicalization (on the other hand). Identifying legitimate predisease can result in useful preventive measures, such as motivating the person to get a healthy amount of physical exercise, but labeling a healthy person with an unfounded notion of predisease can result in overtreatment, such as taking drugs that only help people with severe disease or paying for drug prescription instances whose benefit–cost ratio is minuscule (placing it in the waste category of CMS "waste, fraud, and abuse" classification). Three requirements for the legitimacy of calling a condition a predisease are:
a truly high risk for progression to disease – for example, a pre-cancer will almost certainly turn into cancer over time
actionability for risk reduction – for example, removal of the precancerous tissue prevents it from turning into a potentially deadly cancer
benefit that outweighs the harm of any interventions taken – removing the precancerous tissue prevents cancer, and thus prevents a potential death from cancer.

Types by body system
Mental
Mental illness is a broad, generic label for a category of illnesses that may include affective or emotional instability, behavioral dysregulation, cognitive dysfunction or impairment. Specific illnesses known as mental illnesses include major depression, generalized anxiety disorders, schizophrenia, and attention deficit hyperactivity disorder, to name a few. Mental illness can be of biological (e.g., anatomical, chemical, or genetic) or psychological (e.g., trauma or conflict) origin. It can impair the affected persons ability to work or study and can harm interpersonal relationships. The term insanity is used technically as a legal term.
Organic
An organic disease is one caused by a physical or physiological change to some tissue or organ of the body. The term sometimes excludes infections. It is commonly used in contrast with mental disorders. It includes emotional and behavioral disorders if they are due to changes to the physical structures or functioning of the body, such as after a stroke or a traumatic brain injury, but not if they are due to psychosocial issues.

Stages
In an infectious disease, the incubation period is the time between infection and the appearance of symptoms. The latency period is the time between infection and the ability of the disease to spread to another person, which may precede, follow, or be simultaneous with the appearance of symptoms. Some viruses also exhibit a dormant phase, called viral latency, in which the virus hides in the body in an inactive state. For example, varicella zoster virus causes chickenpox in the acute phase; after recovery from chickenpox, the virus may remain dormant in nerve cells for many years, and later cause herpes zoster (shingles).

Acute disease
An acute disease is a short-lived disease, like the common cold.
Chronic disease
A chronic disease is one that lasts for a long time, usually at least six months. During that time, it may be constantly present, or it may go into remission and periodically relapse. A chronic disease may be stable (does not get any worse) or it may be progressive (gets worse over time). Some chronic diseases can be permanently cured. Most chronic diseases can be beneficially treated, even if they cannot be permanently cured.
Clinical disease
One that has clinical consequences; in other words, the stage of the disease that produces the characteristic signs and symptoms of that disease. AIDS is the clinical disease stage of HIV infection.
Cure
A cure is the end of a medical condition or a treatment that is very likely to end it, while remission refers to the disappearance, possibly temporarily, of symptoms. Complete remission is the best possible outcome for incurable diseases.
Flare-up
A flare-up can refer to either the recurrence of symptoms or an onset of more severe symptoms.
Progressive disease
Progressive disease is a disease whose typical natural course is the worsening of the disease until death, serious debility, or organ failure occurs. Slowly progressive diseases are also chronic diseases; many are also degenerative diseases. The opposite of progressive disease is stable disease or static disease: a medical condition that exists, but does not get better or worse.
Refractory disease
A refractory disease is a disease that resists treatment, especially an individual case that resists treatment more than is normal for the specific disease in question.
Subclinical disease
Also called silent disease, silent stage, or asymptomatic disease. This is a stage in some diseases before the symptoms are first noted.
Terminal phase
If a person will die soon from a disease, regardless of whether that disease typically causes death, then the stage between the earlier disease process and active dying is the terminal phase.
Recovery
Recovery can refer to the repairing of physical processes (tissues, organs etc.) and the resumption of healthy functioning after damage causing processes have been cured.

Extent
Localized disease
A localized disease is one that affects only one part of the body, such as athletes foot or an eye infection.
Disseminated disease
A disseminated disease has spread to other parts; with cancer, this is usually called metastatic disease.
Systemic disease
A systemic disease is a disease that affects the entire body, such as influenza or high blood pressure.

Classification
Diseases may be classified by cause, pathogenesis (mechanism by which the disease is caused), or by symptom(s). Alternatively, diseases may be classified according to the organ system involved, though this is often complicated since many diseases affect more than one organ.
A chief difficulty in nosology is that diseases often cannot be defined and classified clearly, especially when cause or pathogenesis are unknown. Thus diagnostic terms often only reflect a symptom or set of symptoms (syndrome).
Classical classification of human disease derives from the observational correlation between pathological analysis and clinical syndromes. Today it is preferred to classify them by their cause if it is known.The most known and used classification of diseases is the World Health Organizations ICD. This is periodically updated. Currently, the last publication is the ICD-11.

Causes
Only some diseases such as influenza are contagious and commonly believed infectious. The microorganisms that cause these diseases are known as pathogens and include varieties of bacteria, viruses, protozoa, and fungi. Infectious diseases can be transmitted, e.g. by hand-to-mouth contact with infectious material on surfaces, by bites of insects or other carriers of the disease, and from contaminated water or food (often via fecal contamination), etc. Also, there are sexually transmitted diseases. In some cases, microorganisms that are not readily spread from person to person play a role, while other diseases can be prevented or ameliorated with appropriate nutrition or other lifestyle changes.
Some diseases, such as most (but not all) forms of cancer, heart disease, and mental disorders, are non-infectious diseases. Many non-infectious diseases have a partly or completely genetic basis (see genetic disorder) and may thus be transmitted from one generation to another.
Social determinants of health are the social conditions in which people live that determine their health. Illnesses are generally related to social, economic, political, and environmental circumstances. Social determinants of health have been recognized by several health organizations such as the Public Health Agency of Canada and the World Health Organization to greatly influence collective and personal well-being. The World Health Organizations Social Determinants Council also recognizes Social determinants of health in poverty.
When the cause of a disease is poorly understood, societies tend to mythologize the disease or use it as a metaphor or symbol of whatever that culture considers evil. For example, until the bacterial cause of tuberculosis was discovered in 1882, experts variously ascribed the disease to heredity, a sedentary lifestyle, depressed mood, and overindulgence in sex, rich food, or alcohol, all of which were social ills at the time.When a disease is caused by a pathogenic organism (e.g., when malaria is caused by Plasmodium), one should not confuse the pathogen (the cause of the disease) with disease itself. For example, West Nile virus (the pathogen) causes West Nile fever (the disease). The misuse of basic definitions in epidemiology is frequent in scientific publications.

Types of causes
Airborne
An airborne disease is any disease that is caused by pathogens and transmitted through the air.
Foodborne
Foodborne illness or food poisoning is any illness resulting from the consumption of food contaminated with pathogenic bacteria, toxins, viruses, prions or parasites.
Infectious
Infectious diseases, also known as transmissible diseases or communicable diseases, comprise clinically evident illness (i.e., characteristic medical signs or symptoms of disease) resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism. Included in this category are contagious diseases – an infection, such as influenza or the common cold, that commonly spreads from one person to another – and communicable diseases – a disease that can spread from one person to another, but does not necessarily spread through everyday contact.
Lifestyle
A lifestyle disease is any disease that appears to increase in frequency as countries become more industrialized and people live longer, especially if the risk factors include behavioral choices like a sedentary lifestyle or a diet high in unhealthful foods such as refined carbohydrates, trans fats, or alcoholic beverages.
Non-communicable
A non-communicable disease is a medical condition or disease that is non-transmissible. Non-communicable diseases cannot be spread directly from one person to another. Heart disease and cancer are examples of non-communicable diseases in humans.

Prevention
Many diseases and disorders can be prevented through a variety of means. These include sanitation, proper nutrition, adequate exercise, vaccinations and other self-care and public health measures, such as obligatory face mask mandates.

Treatments
Medical therapies or treatments are efforts to cure or improve a disease or other health problems. In the medical field, therapy is synonymous with the word treatment. Among psychologists, the term may refer specifically to psychotherapy or "talk therapy". Common treatments include medications, surgery, medical devices, and self-care. Treatments may be provided by an organized health care system, or informally, by the patient or family members.
Preventive healthcare is a way to avoid an injury, sickness, or disease in the first place. A treatment or cure is applied after a medical problem has already started. A treatment attempts to improve or remove a problem, but treatments may not produce permanent cures, especially in chronic diseases. Cures are a subset of treatments that reverse diseases completely or end medical problems permanently. Many diseases that cannot be completely cured are still treatable. Pain management (also called pain medicine) is that branch of medicine employing an interdisciplinary approach to the relief of pain and improvement in the quality of life of those living with pain.Treatment for medical emergencies must be provided promptly, often through an emergency department or, in less critical situations, through an urgent care facility.

Epidemiology
Epidemiology is the study of the factors that cause or encourage diseases. Some diseases are more common in certain geographic areas, among people with certain genetic or socioeconomic characteristics, or at different times of the year.
Epidemiology is considered a cornerstone methodology of public health research and is highly regarded in evidence-based medicine for identifying risk factors for diseases. In the study of communicable and non-communicable diseases, the work of epidemiologists ranges from outbreak investigation to study design, data collection, and analysis including the development of statistical models to test hypotheses and the documentation of results for submission to peer-reviewed journals. Epidemiologists also study the interaction of diseases in a population, a condition known as a syndemic. Epidemiologists rely on a number of other scientific disciplines such as biology (to better understand disease processes), biostatistics (the current raw information available), Geographic Information Science (to store data and map disease patterns) and social science disciplines (to better understand proximate and distal risk factors). Epidemiology can help identify causes as well as guide prevention efforts.
In studying diseases, epidemiology faces the challenge of defining them. Especially for poorly understood diseases, different groups might use significantly different definitions. Without an agreed-on definition, different researchers may report different numbers of cases and characteristics of the disease.Some morbidity databases are compiled with data supplied by states and territories health authorities, at national levels or larger scale (such as European Hospital Morbidity Database (HMDB)) which may contain hospital discharge data by detailed diagnosis, age and sex. The European HMDB data was submitted by European countries to the World Health Organization Regional Office for Europe.

Burdens of disease
Disease burden is the impact of a health problem in an area measured by financial cost, mortality, morbidity, or other indicators.
There are several measures used to quantify the burden imposed by diseases on people. The years of potential life lost (YPLL) is a simple estimate of the number of years that a persons life was shortened due to a disease. For example, if a person dies at the age of 65 from a disease, and would probably have lived until age 80 without that disease, then that disease has caused a loss of 15 years of potential life. YPLL measurements do not account for how disabled a person is before dying, so the measurement treats a person who dies suddenly and a person who died at the same age after decades of illness as equivalent. In 2004, the World Health Organization calculated that 932 million years of potential life were lost to premature death.The quality-adjusted life year (QALY) and disability-adjusted life year (DALY) metrics are similar but take into account whether the person was healthy after diagnosis. In addition to the number of years lost due to premature death, these measurements add part of the years lost to being sick. Unlike YPLL, these measurements show the burden imposed on people who are very sick, but who live a normal lifespan. A disease that has high morbidity, but low mortality, has a high DALY and a low YPLL. In 2004, the World Health Organization calculated that 1.5 billion disability-adjusted life years were lost to disease and injury. In the developed world, heart disease and stroke cause the most loss of life, but neuropsychiatric conditions like major depressive disorder cause the most years lost to being sick.

Society and culture
How a society responds to diseases is the subject of medical sociology.
A condition may be considered a disease in some cultures or eras but not in others. For example, obesity can represent wealth and abundance, and is a status symbol in famine-prone areas and some places hard-hit by HIV/AIDS. Epilepsy is considered a sign of spiritual gifts among the Hmong people.Sickness confers the social legitimization of certain benefits, such as illness benefits, work avoidance, and being looked after by others. The person who is sick takes on a social role called the sick role. A person who responds to a dreaded disease, such as cancer, in a culturally acceptable fashion may be publicly and privately honored with higher social status. In return for these benefits, the sick person is obligated to seek treatment and work to become well once more. As a comparison, consider pregnancy, which is not interpreted as a disease or sickness, even if the mother and baby may both benefit from medical care.
Most religions grant exceptions from religious duties to people who are sick. For example, one whose life would be endangered by fasting on Yom Kippur or during Ramadan is exempted from the requirement, or even forbidden from participating. People who are sick are also exempted from social duties. For example, ill health is the only socially acceptable reason for an American to refuse an invitation to the White House.The identification of a condition as a disease, rather than as simply a variation of human structure or function, can have significant social or economic implications. The controversial recognition of diseases such as repetitive stress injury (RSI) and post-traumatic stress disorder (PTSD) has had a number of positive and negative effects on the financial and other responsibilities of governments, corporations, and institutions towards individuals, as well as on the individuals themselves. The social implication of viewing aging as a disease could be profound, though this classification is not yet widespread.
Lepers were people who were historically shunned because they had an infectious disease, and the term "leper" still evokes social stigma. Fear of disease can still be a widespread social phenomenon, though not all diseases evoke extreme social stigma.
Social standing and economic status affect health. Diseases of poverty are diseases that are associated with poverty and low social status; diseases of affluence are diseases that are associated with high social and economic status. Which diseases are associated with which states vary according to time, place, and technology. Some diseases, such as diabetes mellitus, may be associated with both poverty (poor food choices) and affluence (long lifespans and sedentary lifestyles), through different mechanisms. The term lifestyle diseases describes diseases associated with longevity and that are more common among older people. For example, cancer is far more common in societies in which most members live until they reach the age of 80 than in societies in which most members die before they reach the age of 50.

Language of disease
An illness narrative is a way of organizing a medical experience into a coherent story that illustrates the sick individuals personal experience.
People use metaphors to make sense of their experiences with disease. The metaphors move disease from an objective thing that exists to an affective experience. The most popular metaphors draw on military concepts: Disease is an enemy that must be feared, fought, battled, and routed. The patient or the healthcare provider is a warrior, rather than a passive victim or bystander. The agents of communicable diseases are invaders; non-communicable diseases constitute internal insurrection or civil war. Because the threat is urgent, perhaps a matter of life and death, unthinkably radical, even oppressive, measures are societys and the patients moral duty as they courageously mobilize to struggle against destruction. The War on Cancer is an example of this metaphorical use of language. This language is empowering to some patients, but leaves others feeling like they are failures.Another class of metaphors describes the experience of illness as a journey: The person travels to or from a place of disease, and changes himself, discovers new information, or increases his experience along the way. He may travel "on the road to recovery" or make changes to "get on the right track" or choose "pathways" </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Hartnup disease and can you explain it in depth? [/INST] Hartnup disease (also known as "pellagra-like dermatosis" and "Hartnup disorder") is an autosomal recessive metabolic disorder affecting the absorption of nonpolar amino acids (particularly tryptophan that can be, in turn, converted into serotonin, melatonin, and niacin). Niacin is a precursor to nicotinamide, a necessary component of NAD+.: 541 The causative gene, SLC6A19, is located on chromosome 5. It is named after the British family, Hartnup, who had this disease.

Signs and symptoms
Hartnup disease manifests during infancy with variable clinical presentation: failure to thrive, photosensitivity, intermittent ataxia, nystagmus, and tremor.Nicotinamide is necessary for neutral amino acid transporter production in the proximal renal tubules found in the kidney, and intestinal mucosal cells found in the small intestine.  Therefore, a symptom stemming from this disorder results in increased amounts of amino acids in the urine.
Pellagra, a similar condition, is also caused by low nicotinamide; this disorder results in dermatitis, diarrhea, and dementia.Hartnup disease is a disorder of amino acid transport in the intestine and kidneys; otherwise, the intestine and kidneys function normally, and the effects of the disease occur mainly in the brain and skin. Symptoms may begin in infancy or early childhood, but sometimes they begin as late as early adulthood. Symptoms may be triggered by sunlight, fever, drugs, or emotional or physical stress.  A period of poor nutrition nearly always precedes an attack. The attacks usually become progressively less frequent with age.  Most symptoms occur sporadically and are caused by a deficiency of niacinamide.  A rash develops on parts of the body exposed to the sun.  Mental retardation, short stature, headaches, unsteady gait, and collapsing or fainting are common.  Psychiatric problems (such as anxiety, rapid mood changes, delusions, and hallucinations) may also result.

Causes
Hartnup disease is inherited as an autosomal recessive trait. Heterozygotes are normal. Consanguinity is common. The failure of amino-acid transport was reported in 1960 from the increased presence of indoles (bacterial metabolites of tryptophan) and tryptophan in the urine of patients as part of a generalized aminoaciduria of the disease. The excessive loss of tryptophan from malabsorption was the cause of the pellagra like symptoms. From studies on ingestion of tryptophan it seemed that there was a generalized problem with amino-acid transport. In 2004, a causative gene, SLC6A19, was located on band 5p15.33. SLC6A19 is a sodium-dependent and chloride-independent neutral amino acid transporter, expressed predominantly in the kidneys and intestine.

Diagnosis
The defective gene controls the absorption of certain amino acids from the intestine and the reabsorption of those amino acids in the kidneys. Consequently, a person with Hartnup disease cannot absorb amino acids properly from the intestine and cannot reabsorb them properly from tubules in the kidneys </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Incontinentia pigmenti and can you explain it in depth? [/INST] Incontinentia pigmenti (IP) is a rare X-linked dominant genetic disorder that affects the skin, hair, teeth, nails and central nervous system. It is named from its appearance under a microscope.The disease is characterized by skin abnormalities that begin in childhood, usually a blistering rash which heals, followed by the development of harder skin growths. The skin may develop grey or brown patches which fade with time. Other symptoms can include hair loss, dental abnormalities, eye abnormalities that can lead to vision loss and lined or pitted fingernails and toenails. Associated problems can include delayed development, intellectual disability, seizures and other neurological problems. Most males with the disease do not survive to childbirth.
Incontinentia pigmenti is caused by a mutation in the IKBKG gene, which encodes the NEMO protein, which serves to protect cells against TNF-alpha-induced apoptosis. A lack of IKBKG therefore makes cells more prone to apoptosis.
There is no specific treatment; individual conditions must be managed by specialists.

Presentation
The skin lesions evolve through characteristic stages:
blistering (from birth to about four months of age),
a wart-like rash (for several months),
swirling macular hyperpigmentation (from about six months of age into adulthood), followed by
linear hypopigmentation.Alopecia, dental anomalies, and dystrophic nails are observed. Some patients have retinal vascular abnormalities predisposing to retinal detachment in early childhood. Cognitive delays or intellectual disability are occasionally seen.The discolored skin is caused by excessive deposits of melanin (normal skin pigment).
Most newborns with IP will develop discolored skin within the first two weeks.
The pigmentation involves the trunk and extremities, is slate-grey, blue or brown, and is distributed in irregular marbled or wavy lines.
The discoloration sometimes fades with age.Neurological problems can include cerebral atrophy, the formation of small cavities in the central white matter of the brain, and the loss of neurons in the cerebellar cortex.
About 20% of children with IP will have slow motor development, muscle weakness in one or both sides of the body, intellectual disability, and seizures.
They are also likely to have visual problems, which can include: crossed eyes, cataracts, retinal detachment, and severe visual loss.
Dental problems are also common, and can include hypodontia, abnormally shaped teeth, and delayed tooth eruption.Breast anomalies can occur in 1% of patients and can include hypoplasia or supernumerary nipples.
Skeletal and structural anomalies can occur in approximately 14% of patients, including:
Somatic asymmetry
Hemivertebrae
Scoliosis
Spina bifida
Syndactyly
Acheiria (congenital absence of the hands—note: other limbs may be affected)
Ear anomalies
Extra ribs
Skull deformities

Genetics
IP is inherited in an X-linked dominant manner. IP is lethal in most, but not all, males. A female with IP may have inherited the IKBKG mutation from either parent or have a new gene mutation. Parents may either be clinically affected or have germline mosaicism. Affected women have a 50% risk of transmitting the mutant IKBKG allele at conception; however, most affected male conceptuses miscarry. Thus, the effective ratio for liveborn children from a mother carrying the mutation is 33% unaffected females, 33% affected females, and 33% unaffected males. Genetic counseling, prenatal testing, and preimplantation genetic diagnosis is available.In females, the cells expressing the mutated IKBKG gene due to lyonization selectively die around the time of birth, so the X-inactivation is extremely skewed.IP is caused by mutations in a gene called NEMO (NF-κB essential modulator).

Diagnosis
The diagnosis of IP is established by clinical findings and occasionally by corroborative skin biopsy </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Effusion and can you explain it in depth? [/INST] In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules. Such a hole is often described as a pinhole and the escape of the gas is due to the pressure difference between the container and the exterior. Under these conditions, essentially all molecules which arrive at the hole continue and pass through the hole, since collisions between molecules in the region of the hole are negligible. Conversely, when the diameter is larger than the mean free path of the gas, flow obeys the Sampson flow law.
In medical terminology, an effusion refers to accumulation of fluid in an anatomic space, usually without loculation. Specific examples include subdural, mastoid, pericardial and pleural effusions.

Etymology
The word effusion derives from the Latin word, effundo, which means "shed, pour forth, pour out, utter, lavish, waste."

Effusion into vacuum
Effusion from an equilibrated container into outside vacuum can be calculated based on kinetic theory. The number of atomic or molecular collisions with a wall of a container per unit area per unit time (impingement rate) is given by:

assuming mean free path is much greater than pinhole diameter and the gas can be treated as an ideal gas.If a small area

        A

    {\displaystyle A}
   on the container is punched to become a small hole, the effusive flow rate will be

where

        M

    {\displaystyle M}
   is the molar mass,

          N

            A

    {\displaystyle N_{A}}
   is the Avogadro constant, and

        R
        =

          N

            A

          k

            B

    {\displaystyle R=N_{A}k_{B}}
   is the gas constant.
The average velocity of effused particles is

Combined with the effusive flow rate, the recoil/thrust force on the system itself is

An example is the recoil force on a balloon with a small hole flying in vacuum.

Measures of flow rate
According to the kinetic theory of gases, the kinetic energy for a gas at a temperature

        T

    {\displaystyle T}
   is

            1
            2

        m

          v

              r
              m
              s

            2

        =

            3
            2

          k

              B

        T

    {\displaystyle {\frac {1}{2}}mv_{\rm {rms}}^{2}={\frac {3}{2}}k_{\rm {B}}T}
  where

        m

    {\displaystyle m}
   is the mass of one molecule,

          v

              r
              m
              s

    {\displaystyle v_{\rm {rms}}}
   is the root-mean-square speed of the molecules, and

          k

              B

    {\displaystyle k_{\rm {B}}}
   is the Boltzmann constant. The average molecular speed can be calculated from the Maxwell speed distribution
as

          v

              a
              v
              g

        =

            8

              /

            3
            π

          v

              r
              m
              s

        ≈
        0.921

          v

              r
              m
              s

    {\textstyle v_{\rm {avg}}={\sqrt {8/3\pi }}\ v_{\rm {rms}}\approx 0.921\ v_{\rm {rms}}}
   (or, equivalently,

          v

              r
              m
              s

        =

            3
            π

              /

            8

          v

              a
              v
              g

        ≈
        1.085

          v

              a
              v
              g

    {\textstyle v_{\rm {rms}}={\sqrt {3\pi /8}}\ v_{\rm {avg}}\approx 1.085\ v_{\rm {avg}}}
  ) </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Parasomnia and can you explain it in depth? [/INST] Parasomnias  are a category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep. Parasomnias are dissociated sleep states which are partial arousals during the transitions between wakefulness, NREM sleep, and REM sleep, and their combinations.

Classification
The newest version of the International Classification of Sleep Disorders (ICSD, 3rd. Ed.) uses State Dissociation as the paradigm for parasomnias. Unlike before, where wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep were considered exclusive states, research has shown that combinations of these states are possible and thus, may result in unusual unstable states that could eventually manifest as parasomnias or as altered levels of awareness.Although the previous definition is technically correct, it contains flaws. The consideration of the State Dissociation paradigm facilitates the understanding of the sleep disorder and provides a classification of 10 core categories.

Non-rapid eye movement (NREM)-related parasomnias
NREM parasomnias are arousal disorders that occur during stage 3 (or 4 by the R&K standardization) of NREM sleep—also known as slow wave sleep (SWS). They are caused by a physiological activation in which the patients brain exits from SWS and is caught in between a sleeping and waking state. In particular, these disorders involve activation of the autonomic nervous system, motor system, or cognitive processes during sleep or sleep-wake transitions.Some NREM parasomnias (sleep-walking, night-terrors, and confusional arousal) are common during childhood but decrease in frequency with increasing age. They can be triggered in certain individuals, by alcohol, sleep deprivation, physical activity, emotional stress, depression, medications, or a fevered illness. These disorders of arousal can range from confusional arousals, somnambulism, to night terrors. Other specific disorders include sleepeating, sleep sex, teeth grinding, rhythmic movement disorder, restless legs syndrome, and somniloquy.

Differential diagnosis for NREM-related parasomnias
Sleep-disordered breathing
REM-related parasomnias
Nocturnal seizures
Psychogenic dissociative disorders

Confusional arousals
Confusional arousal is a condition when an individual awakens from sleep and remains in a confused state. It is characterized by the individuals partial awakening and sitting up to look around. They usually remain in bed and then return to sleep. These episodes last anywhere from seconds to minutes and may not be reactive to stimuli. Confusional arousal is more common in children than in adults. It has a lifetime prevalence of 18.5% in children and a lifetime prevalence of 2.9–4.2% in adults. Infants and toddlers usually experience confusional arousals beginning with large amounts of movement and moaning, which can later progress to occasional thrashings or inconsolable crying. In rare cases, confusional arousals can cause injuries and drowsy driving accidents, thus it can also be considered dangerous. Another sleeping disorder may be present triggering these incomplete arousals.

Somniloquy (sleep talking)
A form of parasomnia where a person will speak during their dreams.

Sleep-related abnormal sexual behavior
Sleep-related abnormal sexual behavior, Sleep sex, or sexsomnia, is a form of confusional arousal that may overlap with somnambulism. Thereby, a person will engage in sexual acts while still asleep. It can include such acts as masturbation, inappropriate fondling themselves or others, having sex with another person; and in more extreme cases, sexual assault. These behaviors are unconscious, occur frequently without dreaming, and bring along clinical, social, and legal implications. It has a lifetime prevalence of 7.1% and an annual prevalence of 2.7%.

Sleepwalking (somnambulism)
Sleepwalking has a prevalence of 1–17% in childhood, with the most frequent occurrences around the age of eleven to twelve. About 4% of adults experience somnambulism.
Normal sleep cycles include states varying from drowsiness all the way to deep sleep. Every time an individual sleeps, he or she goes through various sequences of non-REM and REM sleep. Anxiety and fatigue are often connected with sleepwalking. For adults, alcohol, sedatives, medications, medical conditions and mental disorders are all associated with sleepwalking. Sleep walking may involve sitting up and looking awake when the individual is actually asleep, and getting up and walking around, moving items or undressing themselves. They will also be confused when waking up or opening their eyes during sleep. Sleep walking can be associated with sleeptalking.

Sleep terrors (night terrors/ pavor nocturnus)
Sleep terror is the most disruptive arousal disorder since it may involve loud screams and panic; in extreme cases, it may result in bodily harm or property damage by running about or hitting walls. All attempts to console the individual are futile and may prolong or intensify their confused state. Usually they experience amnesia after the event but it may not be complete amnesia. Up to 3% of adults have sleep terrors and exhibited behavior of this parasomnia can range from mild to extremely violent. This is very prevalent in those who have violent post-traumatic stress disorder (PTSD). They typically occur in stage 3 sleep.

Sleep-related eating disorder (SRED)
The Diagnostic and Statistical Manual of Mental Disorders (DSM-V) classifies sleep-related eating disorder under sleepwalking, while ICSD classifies it as NREM-related parasomnia. It is conceptualized as a mixture of binge-eating behavior and arousal disorder. Thereby, preferentially high-caloric food is consumed in an uncontrolled manner. However, SRED should not be confused with nocturnal eating syndrome, which is characterized by an excessive consumption of food before or during sleep in full consciousness. Since sleep-related eating disorders are associated with other sleep disorders, successful treatment of the latter can reduce symptoms of this parasomnia.

Rapid eye movement (REM)-related parasomnias
REM sleep behavior disorder
Unlike other parasomnias, rapid eye movement sleep behavior disorder (RBD) in which muscle atonia is absent is most common in older adults. This allows the individual to act out their dreams and may result in repeated injury—bruises, lacerations, and fractures—to themselves or others. Patients may take self-protection measures by tethering themselves to bed, using pillow barricades, or sleeping in an empty room on a mattress. Besides ensuring the sleep environment is a safe place, pharmacologic therapy using melatonin and clonazepam is also common as a treatment for RBD, even though they might not eliminate all abnormal behaviours. Before starting a treatment with clonazepam, a screening for obstructive sleep apnea should performed. However, clonazepam needs to be manipulated carefully because of its significant side effects, i.e., morning confusion or memory impairment, mainly in patients with neurodegenerative disorders with dementia.Demographically, 90% of RBD patients are males, and most are older than 50 years of age. However, this prevalence in males could be biased due to the fact that women tends to have a less violent type of RBD, which leads to lower reports at sleep centres and different clinical characteristics. While men might have more aggressive behaviour during dreaming, women have presented more disturbance in their sleep. RBD may be also influenced by a genetic compound, since primary relatives seem to have significantly more chance to develop RBD compared with non-relatives control group.Typical clinical features of REM sleep behavior disorder are:

Male gender predilection
Mean age of onset 50–65 years (range 20–80 years)
Vocalisation, screaming, swearing that may be associated with dreams
Motor activity, simple or complex, that may result in injury to patient or bed-partner
Occurrence usually in latter half of sleep period (REM sleep)
May be associated with neurodegenerative disease Acute RBD occurs mostly as a result of a side-effect in prescribed medication—usually antidepressants. Furthermore, substance abuse or withdrawal can result in RBD.Chronic RBD is idiopathic, meaning of unknown origin, or associated with neurological disorders. There is a growing association of chronic RBD with neurodegenerative disorders—Parkinsons disease, multiple system atrophy (MSA), or dementia—as an early indicator of these conditions by as much as 10 years. RBD associated with neurological disorders is frequently related to abnormal accumulation of alpha-synuclein, and more than 80% of patients with idiopathic RBD might develop Lewy body disease (LBD). Patients with narcolepsy are also more likely to develop RBD.
The diagnosis is based on clinical history, including partners account and needs to be confirmed by polysomnography (PSG), mainly for its accuracy in differentiating RBD from other sleep disorders, since there is a loss of REM atonia with excessive muscle tone. However, screening questionnaires, such as RBDSQ, are also very useful for diagnosing RBD.

Recurrent isolated sleep paralysis
Recurrent isolated sleep paralysis is an inability to perform voluntary movements at sleep onset, or upon waking from sleep. Although the affected individual is conscious and recall is present, the person is not able to speak or move.  However, respiration remains unimpaired. The episodes last seconds to minutes and diminish spontaneously. The lifetime prevalence is 7%. Sleep paralysis is associated with sleep-related hallucinations. Predisposing factors for the development of recurrent isolated sleep paralysis are sleep deprivation, an irregular sleep-wake cycle, e.g. caused by shift work, or stress. A possible cause could be the prolongation of REM sleep muscle atonia upon awakening.

Nightmare disorder
Nightmares are like dreams primarily associated with REM sleep. Nightmare disorder is defined as recurrent nightmares associated with awakening dysphoria that impairs sleep or daytime functioning. It is rare in children, however persists until adulthood. About 2/3 of the adult population report experiencing nightmares at least once in their life.

Catathrenia
Before the ICSD-3, Catathrenia was classified as a rapid-eye-movement sleep parasomnia, but is now classified as sleep-related breathing disorder. It consists of breath holding and expiratory groaning during sleep, is distinct from both somniloquy and obstructive sleep apnea. The sound is produced during exhalation as opposed to snoring which occurs during inhalation. It is usually not noticed by the person producing the sound but can be extremely disturbing to sleep partners, although once aware of it, they tend to be woken up by their own groaning as well.  Bed partners generally report hearing the person take a deep breath, hold it, then slowly exhale; often with a high-pitched squeak or groaning sound.

Sleep-Related painful erections
Painful erections appear only during the sleep. This condition is present during the REM sleep. Sexual activity does not produce any pain. There is not any lesion or physical damage but an hypertonia of the pelvic floor could be one cause. It affects men of all ages but especially from the middle-age. Some pharmacologic treatment as propranolol, clozapine, clonazepam, baclofen and various antidepressants, seems to be effective.

Other parasomnias
Exploding head syndrome
Sleep-related hallucinations
Sleep-related hallucinations are brief episodes of dream-like imagery that can be of any sensory modality, i.e., auditory, visual, or tactile. They are differentiated between hypnagogic hallucination, that occur at sleep onset, and hypnapompic hallucinations, which occur at the transition of sleep to awakening. Although normal individuals have reported nocturnal hallucinations, they are more frequent in comorbidity with other sleep disorders, e.g. narcolepsy.

Sleep enuresis
Parasomnias due to medical disorder
Parasomnias due to medication or substance
Parasomnia, unspecific
Sleep drunkenness, also known as confusional arousal, is the feeling of confusion or sudden action upon waking up from deep sleep. Severe sleep inertia, one cause of oversleeping, is considered to develop sleep drunkenness.

Isolated symptom/normal variant
Sleep talking (somniloquy)
According to ICSD-3 it is not defined a disorder in particular. It is rather an isolated symptom or normal variant and ranges from isolated speech to full conversations without recall. With a lifetime prevalence of 69% it is considered fairly common. Sleep talking is associated with REM-related parasomnias as well as with disorders or arousal. It occurs in all sleep states. As yet, there is no specific treatment for sleeptalking available.

Diagnosis
Parasomnias are most commonly diagnosed by means of questionnaires. These questionnaires include a detailed analyses of the clinical history and contain questions to:

Rule out sleep deprivation
Rule out effects of intoxication or withdrawal
Rule out sleep disorders causing sleep instability
Rule out medical disorders or treatments associated with sleep instability
Confirm presence of NREM parasomnias in other family members and during the patients childhood
Determine the timing of the events
Determine the morphology of the events.Furthermore, a sleep diary is helpful to exclude that sleep deprivation could be a precipitating factor. An additional tool could be the partners log of the events. The following questions should therefore be considered:

Do you or your bed partner believe that you move your arms, legs, or body too much, or have unusual behaviors during sleep?
Do you move while dreaming, as if you are simultaneously attempting to carry out the dream? l Have you ever hurt yourself or your bed partner during sleep?
Do you sleepwalk or have sleep terrors with loud screaming?
Do your legs feel restless or begin to twitch a lot or jump around when you are drowsy or sleepy, either at bedtime or during the day?
Do you eat food or drink fluids without full awareness during the night? Do you wake up in the morning feeling bloated and with no desire to eat breakfast?In potentially harmful or disturbing cases a specialist in sleep disorders should be approached. Video polysomnographic documentation is necessary only in REM sleep behavior disorder (RBD), since it is an essential diagnostic criteria in the ICSD to demonstrate the absence of muscle atonia and to exclude comorbid sleep disorders. For most of the other parasomnias, polysomnographic monitoring is a costly, but still supportive tool in the clinical diagnosis.The use of actigraphy can be promising in the diagnostical assessment of NREM-related parasomnias, for example to rule out sleep deprivation or other sleep disorders, like circadian sleep-wake rhythm disorder which often develops among shift workers. However, there is currently no generally accepted standardized technique available of identifying and quantifying periodic limb movements in sleep (PLMS) that distinguishes movements resulting from parasomnias, nocturnal seizures, and other dyskinesias. Eventually, using actigraphy for parasomnias in general is disputed.

Treatment
Parasomnias can be considered as potentially harmful to oneself as well as to bed partners, and are associated with other disorders. Children with parasomnias do not undergo medical intervention, because they tend to recover the NREM-related disorder with the process of growth. In those cases, the parents receive education on sleep hygiene to reduce and eventually eliminate precipitating factors.In adults psychoeducation about a proper sleep hygiene can reduce the risk to develop parasomnia. Case studies have shown that pharmacological interventions can improve symptoms of parasomnia, however mostly they are accompanied by side-effects. Behavioral treatments, i.e., relaxation therapy, biofeedback, hypnosis, and stress reduction, may also be helpful, but are not considered as universally effective.

Prognosis
NREM-related parasomnias which are common in childhood show a good prognosis, since severity decreases with age, the symptoms tend to resolve during puberty. Adults with NREM-related parasomnias, however, are faced with a stronger persistence of the symptoms, therefore, full remission is quite unlikely and is also associated with violent complications, including homicide. The variant sleep-related eating disorders is chronic, without remission, but treatable.REM sleep behavior disorder (RBD) can mostly be handled well with the use of melatonin or clonazepam. However, there is high comorbidity with neurodegenerative disorders, that is in up to 93% of cases </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Sleep disorder and can you explain it in depth? [/INST] A sleep disorder, or somnipathy, is a medical disorder of an individuals sleep patterns. Some sleep disorders are severe enough to interfere with normal physical, mental, social and emotional functioning. Polysomnography and actigraphy are tests commonly ordered for diagnosing sleep disorders.
Sleep disorders are broadly classified into dyssomnias, parasomnias, circadian rhythm sleep disorders involving the timing of sleep, and other disorders including ones caused by medical or psychological conditions. When a person struggles to fall asleep and/or stay asleep with no obvious cause, it is referred to as insomnia, the most common sleep disorder. Others include sleep apnea, narcolepsy and hypersomnia (excessive sleepiness at inappropriate times), sleeping sickness (disruption of sleep cycle due to infection), sleepwalking, and night terrors.
Sleep disruptions can be caused by various issues, including teeth grinding (bruxism) and night terrors. Management of sleep disturbances that are secondary to mental, medical or substance abuse disorders should focus on the underlying conditions.Primary sleep disorders are common in both children and adults. However, there is a significant lack of awareness in children with sleep disorders, due to most cases being unidentified. Several common factors involved in the onset of a sleep disorder include increased medication use, age-related changes in circadian rhythms, environmental changes, lifestyle changes, pre-diagnosed physiological problems, or stress. Among the elderly, the risk of developing sleep disordered breathing, periodic limb movements, restless legs syndrome, REM sleep behavior disorders, insomnia, and circadian rhythm disturbances is especially increased.

List of conditions
There are a number of sleep disorders. The following list includes some of them:

Bruxism, involuntary grinding or clenching of the teeth while sleeping
Catathrenia, nocturnal groaning during prolonged exhalation
Delayed sleep phase disorder (DSPD), inability to awaken and fall asleep at socially acceptable times but no problem with sleep maintenance, a disorder of circadian rhythms. Other such disorders are advanced sleep phase disorder (ASPD), non-24-hour sleep–wake disorder (non-24) in the sighted or in the blind, and irregular sleep wake rhythm, all much less common than DSPD, as well as the situational shift work sleep disorder.
Fatal familial insomnia, an extremely rare prion disease that causes a complete cessation of sleep, leading quickly to death by sleep deprivation.
Hypopnea syndrome, abnormally shallow breathing or slow respiratory rate while sleeping
Idiopathic hypersomnia, a primary, neurologic cause of long-sleeping, sharing many similarities with narcolepsy
Insomnia disorder (primary insomnia), chronic difficulty in falling asleep and/or maintaining sleep when no other cause is found for these symptoms. Insomnia can also be comorbid with or secondary to other disorders.
Kleine–Levin syndrome, a rare disorder characterized by persistent episodic hypersomnia and cognitive or mood changes
Narcolepsy, characterized by excessive daytime sleepiness (EDS) and so-called "sleep attacks," relatively sudden-onset, irresistible urges to sleep, which may interfere with occupational and social commitments. About 70% of those who have narcolepsy also have cataplexy, a sudden weakness in the motor muscles that can result in collapse to the floor while retaining full conscious awareness.
Night terror, Pavor nocturnus, sleep terror disorder, an abrupt awakening from sleep with behavior consistent with terror
Nocturia, a frequent need to get up and urinate at night. It differs from enuresis, or bed-wetting, in which the person does not arouse from sleep, but the bladder nevertheless empties.
Parasomnias, disruptive sleep-related events involving inappropriate actions during sleep, for example sleepwalking, night-terrors and catathrenia.
Periodic limb movements in sleep (PLMS), sudden involuntary movement of the arms and/or legs during sleep. In the absence of other sleep disorders, PLMS may cause sleep disruption and impair sleep quality, leading to periodic limb movement disorder (PLMD).
Other limb movements in sleep, including hypneic jerks and nocturnal myoclonus.
Rapid eye movement sleep behavior disorder (RBD), acting out violent or dramatic dreams while in REM sleep, sometimes injuring bed partner or self (REM sleep disorder or RSD)
Restless legs syndrome (RLS), an irresistible urge to move legs.
Shift work sleep disorder (SWSD), a situational circadian rhythm sleep disorder. (Jet lag was previously included as a situational circadian rhythm sleep disorder, but it does not appear in DSM-5, see Diagnostic and Statistical Manual of Mental Disorders for more).
Sleep apnea, obstructive sleep apnea, obstruction of the airway during sleep, causing lack of sufficient deep sleep, often accompanied by snoring. Other forms of sleep apnea are less common. Obstructive sleep apnea (OSA) is a medical disorder that is caused by repetitive collapse of the upper airway (back of the throat) during sleep. For the purposes of sleep studies, episodes of full upper airway collapse for at least ten seconds are called apneas.
Sleep paralysis, characterized by temporary paralysis of the body shortly before or after sleep. Sleep paralysis may be accompanied by visual, auditory or tactile hallucinations. It is not a disorder unless severe, and is often seen as part of narcolepsy.
Sleepwalking or somnambulism, engaging in activities normally associated with wakefulness (such as eating or dressing), which may include walking, without the conscious knowledge of the subject.
Somniphobia, one cause of sleep deprivation, a dread/ fear of falling asleep or going to bed. Signs of the illness include anxiety and panic attacks before and during attempts to sleep.

Types
Dyssomnias – A broad category of sleep disorders characterized by either hypersomnia or insomnia. The three major subcategories include intrinsic (i.e., arising from within the body), extrinsic (secondary to environmental conditions or various pathologic conditions), and disturbances of circadian rhythm.Insomnia: Insomnia may be primary or it may be comorbid with or secondary to another disorder such as a mood disorder (i.e., emotional stress, anxiety, depression) or underlying health condition (i.e., asthma, diabetes, heart disease, pregnancy or neurological conditions).
Primary hypersomnia: Hypersomnia of central or brain origin
Narcolepsy: A chronic neurological disorder (or dyssomnia), which is caused by the brains inability to control sleep and wakefulness.
Idiopathic hypersomnia: A chronic neurological disease similar to narcolepsy, in which there is an increased amount of fatigue and sleep during the day. Patients who have idiopathic hypersomnia cannot obtain a healthy amount of sleep for a regular day of activities. This hinders the patients ability to perform well, and patients have to deal with this for the rest of their lives.
Recurrent hypersomnia, including Kleine–Levin syndrome
Post traumatic hypersomnia
Menstrual-related hypersomnia
Sleep disordered breathing (SDB), including (non-exhaustive):
Several types of sleep apnea
Snoring
Upper airway resistance syndrome
Restless leg syndrome
Periodic limb movement disorder
Circadian rhythm sleep disorders
Delayed sleep phase disorder
Advanced sleep phase disorder
Non-24-hour sleep–wake disorder
Parasomnias – A category of sleep disorders that involve abnormal and unnatural movements, behaviors, emotions, perceptions, and dreams in connection with sleep.
Bedwetting or sleep enuresis
Bruxism (Tooth-grinding)
Catathrenia – nocturnal groaning
Exploding head syndrome – Waking up in the night hearing loud noises.
Sleep terror (or Pavor nocturnus) – Characterized by a sudden arousal from deep sleep with a scream or cry, accompanied by some behavioral manifestations of intense fear.
REM sleep behavior disorder
Sleepwalking (or somnambulism)
Sleep talking (or somniloquy)
Sleep sex (or sexsomnia)
Medical or psychiatric conditions that may produce sleep disorders
22q11.2 deletion syndrome
Alcoholism
Mood disorders
Depression
Anxiety disorder
Nightmare disorder
Panic
Psychosis (such as Schizophrenia)
Sleeping sickness – a parasitic disease which can be transmitted by the Tsetse fly.

Causes
A systematic review found that traumatic childhood experiences (such as family conflict or sexual trauma) significantly increases the risk for a number of sleep disorders in adulthood, including sleep apnea, narcolepsy, and insomnia.In addition, an evidence-based synopsis suggests that idiopathic REM sleep behavior disorder (iRBD) may have a hereditary component. A total of 632 participants, half with iRBD and half without, completed self-report questionnaires. The results of the study suggest that people with iRBD are more likely to report having a first-degree relative with the same sleep disorder than people of the same age and sex that do not have the disorder. More research needs to be conducted to further understand the hereditary nature of sleep disorders.
A population susceptible to the development of sleep disorders includes people who have experienced a traumatic brain injury (TBI). Because many researchers have focused on this issue, a systematic review was conducted to synthesize their findings. The results indicate that individuals who experienced a TBI are most disproportionately at risk for developing narcolepsy, obstructive sleep apnea, excessive daytime sleepiness, and insomnia. The studys complete findings can be found in the table below:

Sleep disorders and Neurodegenerative Diseases
Neurodegenerative diseases have often been associated with sleep disorders, mainly when they are characterized by abnormal accumulation of alpha-synuclein, such as multiple system atrophy (MSA), Parkinsons disease (PD) and Lewy body disease (LBD). For instance, people diagnosed with PD have often presented different kinds of sleep concerns, commonly in regard to insomnia (around 70% of the PD population), hypersomnia (more than 50% of the PD population), and REM sleep behavior disorder (RBD) - that may affect around 40% of the PD population and it is associated with increased motor symptoms. Furthermore, RBD has been highlighted as a strong precursor for future development of those neurodegenerative diseases over several years in prior, which seems to be a great opportunity for improving the treatments of the disease.Sleep disturbances have been also observed in Alzheimers disease (AD), affecting about 45% of its population. When based on caregiver reports, this percentage increases to about 70%. As well as in PD population, insomnia and hypersomnia are frequently recognized in AD patients, which have been associated with accumulation of beta-amyloid, circadian rhythm sleep disorders (CRSD) and melatonin alteration. Additionally, changes in sleep architecture are observed in AD. Although sleep architecture seems to naturally change with age, its development appears aggravated in AD patients. SWS potentially decreases (and is sometimes absent), spindles and the length of time spent in REM sleep are also reduced, while its latency increases. Poor sleep onset in AD has been associated with dream-related hallucination, increased restlessness, wandering and agitation that seem related to sundowning - a typical chronobiological phenomenon presented in the disease.The neurodegenerative conditions are commonly related to structural brain impairment, which might disrupt the states of sleep and wakefulness, circadian rhythm, motor or non motor functioning. On the other hand, sleep disturbances are frequently related to worsening patients cognitive functioning, emotional state and quality of life. Furthermore, these abnormal behavioral symptoms negatively contribute to overwhelming their relatives and caregivers. The limited research related to it and the increasing life expectancy calls for a deeper understanding of the relationship between sleep disorders and neurodegenerative disease.

Sleep disturbances and Alzheimers Disease
More than 70% of people with dementia are affected by Alzheimers disease (AD). Despite this high number, our understanding of the underlying mechanisms for disease progression remains very limited. However, recent studies have highlighted a link between sleep disturbances and Alzheimers disease.Sleep changes with normal aging. Over time, a decrease in time sleeping and a decrease in the quantity of NREM sleep can be observed, specifically in NREM SWS (less than 10% of the SWS is maintained). Older people also are more prone to insomnia or sleep apnea.In Alzheimers disease, in addition to cognitive decline and memory impairment, there are also significant sleep disturbances with modified sleep architecture. The latter may consist in sleep fragmentation, reduced sleep duration, insomnia, increased daytime napping, decreased quantity of some sleep stages, and a growing resemblance between some sleep stages (N1 and N2). More than 65% of people with Alzheimers disease have this type of sleep disturbance.One factor that could explain this change in sleep architecture is a change in circadian rhythm, which regulates sleep. A disruption of the circadian rhythm would generate sleep disturbances. Some studies show that people with AD have a delayed circadian rhythm, whereas in normal aging, an advanced circadian rhythm is present.In addition to these psychological symptoms, at a neurological level there are two main symptoms of Alzheimers disease. The first is an accumulation of beta-amyloid waste forming aggregate "plaques". The second is an accumulation of tau protein.It has been shown that the sleep-wake cycle acts on the beta-amyloid burden, which is a central component found in AD. As individuals awaken, the production of beta-amyloid protein will be more consistent than its production during sleep. This is explained by two phenomena. The first is that the metabolic activity will be higher during waking, thus resulting in greater secretion of beta-amyloid protein. The second is that oxidative stress will also increase, which leads to greater AB production.On the other hand, it is during sleep that beta-amyloid residues are degraded to prevent plaque formation. The glymphatic system is responsible for this through the phenomenon of glymphatic clearance. Thus, during wakefulness, the AB burden is greater because the metabolic activity and oxidative stress are higher, and there is no protein degradation by the glymphatic clearance. During sleep, the burden is reduced as there is less metabolic activity and oxidative stress (in addition to the glymphatic clearance that occurs).Glymphatic clearance occurs during the NREM SWS sleep. This sleep stage decreases in normal aging, resulting in less glymphatic clearance and increased AB burden that will form AB plaques. Therefore, sleep disturbances in individuals with AD will amplify this phenomenon.
The decrease in the quantity and quality of the NREM SWS, as well as the disturbances of sleep will therefore increase the AB plaques. This initially occurs in the hippocampus, which is a brain structure integral in long-term memory formation. Hippocampus cell death occurs, which contributes to diminished memory performance and cognitive decline found in AD.Although the causal relationship is unclear, the development of AD correlates with the development of prominent sleep disorders. In the same way, sleep disorders exacerbate disease progression, forming a positive feedback relationship. As a result, sleep disturbances are no longer only a symptom of AD; the relationship between sleep disturbances and AD is bidirectional.At the same time, it has been shown that memory consolidation in long-term memory (which depends on the hippocampus) occurs during NREM sleep. This indicates that a decrease in the NREM sleep will result in less consolidation, resulting in poorer memory performances in hippocampal-dependent long-term memory. This drop in performance is one of the central symptoms of AD.Recent studies have also linked sleep disturbances, neurogenesis and AD. The subgranular zone and the subventricular zone continued to produce new neurons in adult brains. These new cells are then incorporated into neuronal circuits and the subragranular zone, which is found in the hippocampus. These new cells contribute to learning and memory, playing an essential role in hippocampal-dependent memory.However, recent studies have shown that several factors can interrupt neurogenesis, including stress and prolonged sleep deprivation (more than one day). The sleep disturbances encountered in AD could therefore suppress neurogenesis—and thus impair hippocampal functions. This would contribute to diminished memory performances and the progression of AD, and the progression of AD would aggravate sleep disturbances.Changes in sleep architecture found in patients with AD occur during the preclinical phase of AD. These changes could be used to detect those most at risk of developing AD. However, this is still only theoretical.
While the exact mechanisms and the causal relationship between sleep disturbances and AD remains unclear, these findings already provide a better understanding and offer possibilities to improve targeting of at-risk populations—and the implementation of treatments to curb the cognitive decline of AD patients.

Sleep disorder symptoms in psychiatric illnesses
Schizophrenia
In individuals with psychiatric illnesses sleep disorders may include a variety of clinical symptoms, including but not limited to: excessive daytime sleepiness, difficulty falling asleep, difficulty staying asleep, nightmares, sleep talking, sleepwalking, and poor sleep quality. Sleep disturbances - insomnia, hypersomnia and delayed sleep-phase disorder - are quite prevalent in severe mental illnesses such as psychotic disorders. In those with schizophrenia, sleep disorders contribute to cognitive deficits in learning and memory. Sleep disturbances often occur before the onset of psychosis.
Sleep deprivation can also produce hallucinations, delusions and depression. A 2019 study investigated the three above-mentioned sleep disturbances in schizophrenia-spectrum (SCZ) and bipolar (BP) disorders in 617 SCZ individuals, 440 BP individuals, and 173 healthy controls (HC). Sleep disturbances were identified using the Inventory for Depressive Symptoms - clinician rated scale (IDS-C). Results suggested that at least one type of sleep disturbance was reported in 78% of the SCZ population, in 69% individuals with BD, and in 39% of healthy controls. The SCZ group reported the most number of sleep disturbances compared to the BD and HC groups; specifically, hypersomnia was more frequent among individuals with SCZ, and delayed sleep phase disorder was three times more common in the SCZ group compared to the BD group. Insomnias were the most frequently reported sleep disturbance across all three groups.

Bipolar disorder
One of the main behavioral symptoms of bipolar disorder is abnormal sleep. Studies have suggested that 23-78% of individuals with bipolar disorders consistently report symptoms of excessive time spent sleeping, or hypersomnia. The pathogenesis of bipolar disorder, including the higher risk of suicidal ideation, could possibly be linked to circadian rhythm variability, and sleep disturbances are a good predictor of mood swings. The most common sleep-related symptom of bipolar disorder is insomnia, in addition to hypersomnia, nightmares, poor sleep quality, OSA, extreme daytime sleepiness, etc. Moreover, animal models have shown that sleep debt can induce episodes of bipolar mania in laboratory mice, but these models are still limited in their potential to explain bipolar disease in humans with all its multifaceted symptoms, including those related to sleep disturbances.

Major depressive disorder (MDD)
Sleep disturbances (insomnia or hypersomnia) are not a necessary diagnostic criterion—but one of the most frequent symptoms of individuals with major depressive disorder (MDD). Among individuals with MDD, insomnia and hypersomnia have prevalence estimates of 88% and 27%, respectively, whereas individuals with insomnia have a threefold increased risk of developing MDD. Depressed mood and sleep efficiency strongly co-vary, and while sleep regulation problems may precede depressive episodes, such depressive episodes may also precipitate sleep deprivation. Fatigue, as well as sleep disturbances such as irregular and excessive sleepiness, are linked to symptoms of depression. Recent research has even pointed to sleep problems and fatigues as potential driving forces bridging MDD symptoms to those of co-occurring generalized anxiety disorder.

Treatment
Treatments for sleep disorders generally can be grouped into four categories:

Behavioral and psychotherapeutic treatment
Rehabilitation and management
Medication
Other somatic treatmentNone of these general approaches are sufficient for all patients with sleep disorders. Rather, the choice of a specific treatment depends on the patients diagnosis, medical and psychiatric history, and preferences, as well as the expertise of the treating clinician. Often, behavioral/psychotherapeutic and pharmacological approaches may be compatible, and can effectively be combined to maximize therapeutic benefits.
Management of sleep disturbances that are secondary to mental, medical, or substance abuse disorders should focus on the underlying conditions. Medications and somatic treatments may provide the most rapid symptomatic relief from certain disorders, such as narcolepsy, which is best treated with prescription drugs such as modafinil. Others, such as chronic and primary insomnia, may be more amenable to behavioral interventions—with more durable results.
Chronic sleep disorders in childhood, which affect some 70% of children with developmental or psychological disorders, are under-reported and under-treated. Sleep-phase disruption is also common among adolescents, whose school schedules are often incompatible with their natural circadian rhythm. Effective treatment begins with careful diagnosis using sleep diaries and perhaps sleep studies. Modifications in sleep hygiene may resolve the problem, but medical treatment is often warranted.Special equipment may be required for treatment of several disorders such as obstructive apnea, circadian rhythm disorders and bruxism. In severe cases, it may be necessary for individuals to accept living with the disorder, however well managed.
Some sleep disorders have been found to compromise glucose metabolism.

Allergy treatment
Histamine plays a role in wakefulness in the brain. An allergic reaction over produces histamine, causing wakefulness and inhibiting sleep. Sleep problems are common in people with allergic rhinitis. A study from the N.I.H. found that sleep is dramatically impaired by allergic symptoms, and that the degree of impairment is related to the severity of those symptoms. Treatment of allergies has also been shown to help sleep apnea.

Acupuncture
A review of the evidence in 2012 concluded that current research is not rigorous enough to make recommendations around the use of acupuncture for insomnia. The pooled results of two trials on acupuncture showed a moderate likelihood that there may be some improvement to sleep quality for individuals with insomnia.: 15  This form of treatment for sleep disorders is generally studied in adults, rather than children. Further research would be needed to study the effects of acupuncture on sleep disorders in children.

Hypnosis
Research suggests that hypnosis may be helpful in alleviating some types and manifestations of sleep disorders in some patients. "Acute and chronic insomnia often respond to relaxation and hypnotherapy approaches, along with sleep hygiene instructions." Hypnotherapy has also helped with nightmares and sleep terrors. There are several reports of successful use of hypnotherapy for parasomnias specifically for head and body rocking, bedwetting and sleepwalking.Hypnotherapy has been studied in the treatment of sleep disorders in both adults and children.

Music therapy
Although more research should be done to increase the reliability of this method of treatment, research suggests that music therapy can improve sleep quality in acute and chronic sleep disorders. In one particular study, participants (18 years or older) who had experienced acute or chronic sleep disorders were put in a randomly controlled trial, and their sleep efficiency, in the form of overall time asleep, was observed. In order to assess sleep quality, researchers used subjective measures (i.e. questionnaires) and objective measures (i.e. polysomnography). The results of the study suggest that music therapy did improve sleep quality in subjects with acute or chronic sleep disorders, though only when tested subjectively. Although these results are not fully conclusive and more research should be conducted, it still provides evidence that music therapy can be an effective treatment for sleep disorders.In another study specifically looking to help people with insomnia, similar results were seen. The participants that listened to music experienced better sleep quality than those who did not listen to music. Listening to slower pace music before bed can help decrease the heart rate, making it easier to transition into sleep. Studies have indicated that music helps induce a state of relaxation that shifts an individuals internal clock towards the sleep cycle. This is said to have an effect on children and adults with various cases of sleep disorders. Music is most effective before bed once the brain has been conditioned to it, helping to achieve sleep much faster.

Melatonin
Research suggests that melatonin is useful in helping people fall asleep faster (decreased sleep latency), stay asleep longer, and experience improved sleep quality. To test this, a study was conducted that compared subjects who had taken melatonin to subjects with primary sleep disorders who had taken a placebo. Researchers assessed sleep onset latency, total minutes slept, and overall sleep quality in the melatonin and placebo groups to note the differences. In the end, researchers found that melatonin decreased sleep onset latency and increased total sleep time  but had an insignificant and inconclusive impact on the quality of sleep compared to the placebo group.

Sleep medicine
Due to rapidly increasing knowledge and understanding of sleep in the 20th century, including the discovery of REM sleep in the 1950s and circadian rhythm disorders in the 70s and 80s, the medical importance of sleep was recognized. By the 1970s in the US, clinics and laboratories devoted to the study of sleep and sleep disorders had been founded, and a need for standards arose. The medical community began paying more attention to primary sleep disorders, such as sleep apnea, as well as the role and quality of sleep in other conditions.

Specialists in sleep medicine were originally and continue to be certified by the American Board of Sleep Medicine. Those passing the Sleep Medicine Specialty Exam received the designation "diplomate of the ABSM." Sleep medicine is now a recognized subspecialty within internal medicine, family medicine, pediatrics, otolaryngology, psychiatry and neurology in the United States. Certification in Sleep medicine shows that the specialist:"has demonstrated expertise in the diagnosis and management of clinical conditions that occur during sleep, that disturb sleep, or that are affected by disturbances in the wake-sleep cycle. This specialist is skilled in the analysis and interpretation of comprehensive polysomnography, and well-versed in emerging research and management of a sleep laboratory."
Competence in sleep medicine requires an understanding of a myriad of very diverse disorders. Many of which present with similar symptoms such as excessive daytime sleepiness, which, in the absence of volitional sleep deprivation, "is almost inevitably caused by an identifiable and treatable sleep disorder", such as sleep apnea, narcolepsy, idiopathic hypersomnia, Kleine–Levin syndrome, menstrual-related hypersomnia, idiopathic recurrent stupor, or circadian rhythm disturbances. Another common complaint is insomnia, a set of symptoms which can have a great many different causes, physical and mental. Management in the varying situations differs greatly and cannot be undertaken without a correct diagnosis.Sleep dentistry (bruxism, snoring and sleep apnea), while not recognized as one of the nine dental specialties, qualifies for board-certification by the American Board of Dental Sleep Medicine (ABDSM). The qualified dentists collaborate with sleep physicians at accredited sleep centers, and can provide oral appliance therapy and upper airway surgery to treat or manage sleep-related breathing disorders. The resulting diplomate status is recognized by the American Academy of Sleep Medicine (AASM), and these dentists are organized in the Academy of Dental Sleep Medicine (USA).Occupational therapy is an area of medicine that can also address a diagnosis of sleep disorder, as rest and sleep is listed in the Occupational Therapy Practice Framework (OTPF) as its own occupation of daily living.  Rest and sleep are described as restorative in order to support engagement in other occupational therapy occupations.  In the OTPF, the occupation of rest and sleep is broken down into rest, sleep preparation, and sleep participation.  Occupational therapists have been shown to help improve restorative sleep through the use of assistive devices/equipment, cognitive behavioral therapy for Insomnia, therapeutic activities, and/or lifestyle interventions.In the UK, knowledge of sleep medicine and possibilities for diagnosis and treatment seem to lag. The Imperial College Healthcare shows attention to obstructive sleep apnea syndrome (OSA) and very few other sleep disorders. Some NHS trusts have specialist clinics for respiratory and/or neurological sleep medicine.

Epidemiology
Children and young adults
According to one meta-analysis of sleep disorders in children, confusional arousals and sleepwalking are the two most common sleep disorders among children. An estimated 17.3% of kids between 3 and 13 years old experience confusional arousals. About 17% of children sleepwalk, with the disorder being more common among boys than girls, the peak ages of sleepwalking are from 8 to 12 years old.A different systematic review offers a high range of prevalence rates of sleep bruxism for children. Parasomnias like sleepwalking and talking typically occur during the first part of an individuals sleep cycle, the first slow wave of sleep  During the first slow wave of sleep period of the sleep cycle the mind and body slow down causing one to feel drowsy and relaxed. At this stage it is the easiest to wake up, therefore many children do not remember what happened during this time.
Nightmares are also considered a parasomnia among children, who typically remember what took place during the nightmare. However, nightmares only occur during the last stage of sleep - Rapid Eye Movement (REM) sleep. REM is the deepest stage of sleep, it is named for the host of neurological and physiological responses an individual can display during this period of the sleep cycle which are similar to being awake.
Between 15.29% and 38.6% of preschoolers grind their teeth at least one night a week. All but one of the included studies reports decreasing bruxist prevalence as age increased, as well as a higher prevalence among boys than girls.Another systematic review noted 7-16% of young adults have delayed sleep phase disorder. This disorder reaches peak prevalence when people are in their 20s.  Between 20 and 26% of adolescents report a sleep onset latency of greater than 30 minutes. Also, 7-36% have difficulty initiating sleep.  Asian teens tend to have a higher prevalence of all of these adverse sleep outcomes—than their North American and European counterparts.By adulthood, parasomnias can normally be resolved due to a persons growth; however, 4% of people have recurring symptoms.

Effects of Untreated Sleep Disorders
Children and young adults who do not get enough sleep due to sleep disorders also have many other health problems such as obesity and physical problems where it could interfere with everyday life. It is recommended that children and young adults stick to the hours of sleep recommended by the CDC, as it helps increase mental health, physical health, and more.

Insomnia
Insomnia is a prevalent form of sleep deprivation. Individuals with insomnia may have problems falling asleep, staying asleep, or a combination of both resulting in hyposomnia - i.e. insufficient quantity and poor quality of sleep.Combining results from 17 studies on insomnia in China, a pooled prevalence of 15.0% is reported for the country.  This result is consistent among other East Asian countries; however, this is considerably lower than a series of Western countries (50.5% in Poland, 37.2% in France and Italy, 27.1% in USA). Men and women residing in China experience insomnia at similar rates.A separate meta-analysis focusing on this sleeping disorder in the elderly mentions that those with more than one physical or psychiatric malady experience it at a 60% higher rate than those with one condition or less. It also notes a higher prevalence of insomnia in women over the age of 50 than their male counterparts.A study that was resulted from a collaboration between Massachusetts General Hospital and Merck describes the development of an algorithm to identify patients with sleep disorders using electronic medical records. The algorithm that incorporated a combination of structured and unstructured variables identified more than 36,000 individuals with physician-documented insomnia.Insomnia can start off at the basic level but about 40% of people who struggle with insomnia have worse symptoms. There are treatments that can help with insomnia and that includes medication, planning out a sleep schedule, limiting oneself from caffeine intake, and cognitive behavioral therapy.

Obstructive sleep apnea
Obstructive sleep apnea (OSA) affects around 4% of men and 2% of women in the United States </s>


<s> [INST] <<SYS>> You are a responsible assistant committed to providing accurate and helpful responses. Avoid sharing harmful or biased content. Clarify any unclear or incorrect questions rather than providing false or misleading information. <</SYS>> What is Murray Valley encephalitis virus and can you explain it in depth? [/INST] Murray Valley encephalitis virus (MVEV) is a zoonotic flavivirus endemic to northern Australia and Papua New Guinea. It is the causal agent of Murray Valley encephalitis (MVE; previously known as Australian encephalitis or Australian X disease). In humans, it can cause permanent neurological disease or death. MVEV is related to Kunjin virus, which has a similar ecology, but a lower morbidity rate.  Although the arbovirus is endemic to Northern Australia, it has occasionally spread to the southern states during times of heavy rainfall during the summer monsoon season via seasonal flooding of the Murray-Darling River system.  These outbreaks can be "...decades apart, with no or very few cases identified in between".

Vector
MVEV is a mosquito-borne virus that is maintained in a bird-mosquito-bird cycle </s>