Understanding Arthritis Pain
What Causes Arthritis PainUnderstand why you hurt, and learn the different types of pain.
With arthritis comes joint pain. Yet do you know why your joints hurt so much? The series of events that ultimately make you reach for your ice pack or bottle of analgesics involves a complex interaction between your brain and body.
Here’s a look inside the pain process, and how the type of pain you have determines its treatment.
The Pain Process
Though pain is never pleasant, it’s an important signal our bodies use to warn there’s something wrong. Usually, what’s wrong is that you have an injury of some kind, but in some cases what is wrong is that your body is misfiring pain signals.
When you have an injury - in the case of arthritis, an injury to your joints - the damaged tissues release chemicals that alert nearby sensory nerves. These nerves carry the message up your spinal cord to your brain. Your brain processes the message and sends a signal to your motor nerves to take action. So if you start to cut yourself while chopping tomatoes or you touch a hot pan you’ll pull away before you cause more damage.
Besides removing the source of injury, your body has other ways of managing pain. One method is to release painkilling chemicals, called endorphins. The brain also sends signals through the nerves to block additional pain messages from being received - thereby cutting off the sensation of pain.
Types of Pain
Doctors classify pain into two categories based on its duration:
Acute pain happens when you have a disease or injury. It is part of your body’s warning system. You’ll experience acute pain if you burn your hand on the stove, pull a muscle, have knee surgery or get a kidney stone. The pain may be momentary - the cut of a knife before you pull your hand away. Or, it can last for days or weeks - like a tooth that throbs until you can get to the dentist to have it filled. Some acute pain - for example an arthritis flare or gout attack - comes and goes.
Acute pain often is described as sharp, throbbing, shooting or stinging, though it can also be mild. It usually improves once the cause has been treated. Acute pain that isn’t resolved can eventually turn into chronic pain.
Chronic pain lasts for at least three months, but it can continue for many more months, and even years. Arthritis pain, migraine headaches, nerve damage, and low back pain are examples of this type of pain. Chronic pain is often described as an aching, dull, burning or throbbing.
Pain can continue long-term because there’s no treatment for your condition, or your doctor can’t find the source. Pain can also be self-perpetuating. Over time, the constant barrage of pain signals can change nerve cells in your brain and spinal cord. So even after the injury has healed or the condition has been treated, you’ll still feel the discomfort. In a sense, chronic pain becomes its own disease. This is the case with complex regional pain syndrome, fibromyalgia and other chronic pain conditions.
Pain is also divided into categories according to its source and characteristics – nociceptive and neuropathic pain being the two most prominent. It’s important to distinguish between the two types, because each is treated differently. Centralized pain is an important and complex category of pain.
Nociceptive pain is the immediate cause-effect pain you feel in the midst of an injury or illness. Nociceptors are receptors around your body that detect when there’s a threat to your body, and signal your brain to respond to that threat. Pain relievers such as NSAIDs (ibuprofen, aspirin) or opioids work well at treating nociceptive pain, because they interrupt the transmission of pain signals from nerves to your brain or from your brain back down to the location of injury.
Neuropathic pain is due to nerve damage that makes pain signals continue to fire, even after the immediate cause has been removed. Neuropathic pain can produce unusual sensations, like a tingling or electric feeling. Neuropathic pain can be especially frustrating because it doesn’t respond well to pain relieving medication. Instead, treatments target the affected nerves. One therapy for neuropathic pain, called neurostimulation, sends an electric current to the spinal cord. This creates an alternate sensation that prevents the original pain signals from reaching the brain.
Finding Pain Relief
Sometimes the source of pain - especially chronic pain - might not be immediately apparent. It can be frustrating and upsetting to live with a pain you can’t effectively address. Even though pain isn’t always curable, you and your doctor can work together to develop a comprehensive pain management plan that will bring you relief.
Sources of Arthritis PainDifferent types of arthritis can cause different types of pain.
Arthritis and related diseases can cause debilitating, life-changing pain. According to the Centers for Disease Control and Prevention, more than one-third of the adults who have arthritis report that it limits their leisure activities and work. And 25 percent of them say it causes severe pain (seven or higher on a zero to 10 point scale).
There are more than 100 different forms of arthritis and related diseases. The most common types include osteoarthritis (OA), rheumatoid arthritis (RA), psoriatic arthritis (PsA), fibromyalgia and gout. All of them cause pain in different ways.
In osteoarthritis (OA), the protective cartilage inside the joint breaks down. This makes movement of affected joints more difficult and painful. In time, bones of the joint may rub directly against one another, causing severe pain. Pain can also come from parts of your joint other than the cartilage, such as bone, synovium and ligaments. The intensity of OA pain varies from person to person and can range from mild to severe.
In rheumatoid arthritis (RA), the joints and other organs are attacked by the body’s own immune system. The immune system normally protects a person from viruses, bacteria and other invaders. In people with autoimmune diseases like RA, it becomes overactive and attacks healthy tissue. In the case of RA, the immune system primarily goes after the lining of the joints, called the synovium. Over time, the persistent inflammation breaks down the joint and damages it permanently.
Pain in RA can come from other parts of your joint besides the synovium, such as bone and ligaments.
Psoriatic arthritis (PsA) is an autoimmune inflammatory disease in which the immune system attacks the body, causing inflammation and pain. PsA affects the joints, causing arthritis; the connective tissue where tendons or ligaments attach to bones, causing enthesitis; and the skin, causing psoriasis.
Fibromyalgia is considered a central pain syndrome. This means that the brain and spinal cord process pain signals differently. A touch or movement that doesn't cause pain for others may feel painful to you (this is called allodynia). Something that is mildly painful to someone without fibromyalgia may hurt you even more (this is called hyperalgesia).
Fibromyalgia is characterized by widespread pain. It may come and go or be constant. Besides pain, fibromyalgia is associated with other symptoms, such as fatigue, sleep problems, inability to concentrate and mood troubles.
Gout is a form of inflammatory arthritis, but it does not cause body-wide inflammation like RA or PsA does. In gout, uric acid crystals are the problem. If your body produces too much uric acid or if you are unable to remove the excess fast enough, it can build up in the blood (called hyperuricemia). Excess uric acid can form crystals in your joints. This results in extremely painful joint inflammation. Gout usually strikes in the large joint of the big toe, but can also affect other joints. With a gout flare, you can go to bed feeling fine and wake up with excruciating pain.
Lupus is an autoimmune inflammatory disease that affects many parts of the body, including the joints, kidneys, skin, blood, brain and other organs. It can cause joint pain, fatigue, hair loss, sensitivity to light, fever, rash and kidney problems.
Back Pain can be a symptom of several forms of arthritis and related conditions, including ankylosing spondylitis, psoriatic arthritis and fibromyalgia. Most back pain, however, is the result of some type of injury, such lifting or bending improperly, a sports injury or an automobile accident.
Other Musculoskeletal Pain
Soft-tissue rheumatic conditions can also cause pain. In these conditions, muscles, connective tissues such as tendons and ligaments, and bursae become inflamed and painful.
Factors that Affect Arthritis PainEveryone feels arthritis pain differently. Find out why.
How can two people have the exact same amount of joint damage, yet one is in agony while the other feels modest discomfort? The perception of pain starts as a series of biochemical processes - chemical and electrical signals that travel from the injured area and alert your brain that you're hurt. From there, things get personal. Everyone's threshold and tolerance for pain is unique.
"Pain is obviously subjective, and one person's experience cannot be compared to another's," says Joshua Goldner, MD, medical director of pain management at Akron General Hospital in Ohio. "A multitude of factors go into it." Everything from emotions to other medical conditions can shape your response to pain.
Factors That Influence Your Perception of Pain
Besides physical features, like the amount of joint damage and inflammation you have, a number of other factors determine how intensely you feel pain. These include:
Pain becomes a bigger concern the older you get, with as many as 75% of adults age 65 and older reporting persistent pain from arthritis and other chronic conditions. Brain regions that process pain change in structure and function with age, but that doesn't necessarily mean you'll get any reprieve from discomfort in your later years. "In the past, people thought that older people didn't feel pain as intensely…that their nerve endings became less sensitive," Dr. Goldner says. But recent studies of pain sensitivity have shown conflicting results. Sometimes the sensation of pain is dampened in older adults and sometimes it's enhanced. The intensity depends on the type of pain you have, and how long it lasts.
Almost four out of five older adults live with not one, but multiple chronic health conditions. When these health problems trigger pain, the constant barrage of pain signals can create a hypersensitivity that heightens the discomfort. Living with other medical conditions can also influence the way you manage pain - but not always in a negative way. "It can give people a perspective, as well," Dr. Goldner says.
Research on the genetics of pain is still relatively new, but some early studies suggest we inherit a genetic vulnerability to pain sensitivity in much the same way we inherit susceptibility to disease. Scientists have pinpointed a number of genetic variations that make us more likely to develop chronic pain conditions and have a naturally higher or lower pain threshold than someone else.
Women are more likely to develop chronic pain conditions, including fibromyalgia, osteoarthritis and rheumatoid arthritis. Research also indicates that women feel pain more intensely than men. Sex hormones may play a role in women's perception of pain and their likelihood of developing chronic pain conditions.
Pain is more than just a physical experience. It affects your emotions, too. Pain and depression are closely linked. People with chronic pain are about three times more likely to develop depression and other mood disorders, and those with depression are three times more likely to have chronic pain. "Some of the same chemicals that are depleted in depression impact the neurotransmission of pain," Dr. Goldner says. Certain depression medicines can relieve pain. People who are depressed can also feel like their pain is harder to control. Talk therapy can help with feelings of control.
Having caring family members, friends or members of a religious group around you can improve your ability to cope with pain. "When you are in a good place psychologically and you have good support around you, generally pain is affected in a positive way," says Dr. Goldner. Yet pain can make you withdraw from your usual social circles. When you're lonely your unhappiness grows, and with it, your pain increases.
Dr. Goldner explains, "If you address the pain, sometimes that patient will be motivated enough to break that cycle, which leads to a successful outcome."
Joining a support group or meeting with a therapist can improve your outlook and ability to cope with pain.
Dealing With the Feeling of Pain
No matter how you perceive pain, it can be a disruptive force in your life. Constant pain can negatively affect your career and home life. That's why it's important to understand what factors besides physical joint damage exacerbate your pain. Then, work with your doctor to develop a comprehensive and effective pain management plan.
The Emotion–Pain Connection Chronic pain and negative emotions often exist in a circular relationship, each making the other worse. Break the cycle.
Although it may feel like it's coming from your joints, pain - particularly the chronic pain common to arthritis - is also an expression of your state of mind. If you're depressed or anxious, you'll very likely hurt more than when your mood is lighter or more balanced. The fact that pain itself is depressing and worrying only makes the problem worse.
Chronic pain and emotions are so intertwined, in fact, says psychiatrist and palliative medicine physician David Buxton, MD, that's it's often hard to tell where one ends and the other begins. People with depression, for example, have about three times the risk of those without it of developing chronic pain. And, those with chronic pain have about the same increase in risk for winding up with clinical depression.
"People who tend to be depressed or anxious are more susceptible to pain," says Dr. Buxton, clinical assistant professor of medicine at Virginia Commonwealth University and director of the private Center for Palliative Psychiatry, both in Richmond. Depression and anxiety can intensify feelings, including pain, hopelessness and sadness, he says. "Mentally, emotionally and physically, everything sensory, including pain, ratchets up."
Multiple studies of osteoarthritis, rheumatoid arthritis, lupus and fibromyalgia show that people who experience more negative emotions also report more pain. Not surprisingly, people with these conditions also have substantially higher rates of depression and other mood problems compared with those without arthritis and related conditions.
Relieving depression and anxiety makes people feel better physically, too, and most types of medications used to treat these conditions can also be prescribed to help relieve pain.
Advanced imaging of brain processes is helping scientists understand why the mind-body connection is so strong.
Pain and the Brain
"Pain-related signals reach the brain through multiple pathways, but pain is constructed in the brain," explains Tor Wager, PhD, director of the Cognitive and Affective Neuroscience Lab at the University of Colorado at Boulder. There, he and other researchers use techniques like functional magnetic resonance imaging to look at the brain pathways that generate and regulate pain and emotion.
"All of the regions targeted by pain-related signaling from the body have other functions - some help regulate blood pressure and other aspects of physiology, others participate in creating strong emotional responses, and yet others help you learn what to do and not do in the future. So, pain-related signals interface with other brain processes in many ways," he says.
The way people interpret and cope with their emotions and pain, for example, drive the patterns created by the brain. These patterns shape how we remember our pain, and those memories, in turn, strongly influence what we feel in the present, says Dr. Buxton.
Another way to put it, says Wager, is that, "our level of fear of pain and the narrative we tell ourselves about pain can influence how our brain learns to deal with it across time."
Fortunately, says Buxton, our brains are very "plastic," meaning they respond eagerly to retraining, redirection and reframing. This can help break down problematic, and sometimes literally painful, mental patterns.
Calming Mind and Body
Cognitive behavioral therapy (CBT). People with arthritis can use CBT to reshape their response to chronic pain and unhelpful thought patterns, says Dr. Buxton. "CBT, which teaches people to recognize and change negative thought patterns, can also really change the way people view the world and how they're coping," he says. Studies have shown, for example, that six weeks of CBT improves depression, fatigue and feelings of helplessness in people with rheumatoid arthritis.
Psychologists and other therapists currently deliver CBT, but researchers are looking at ways to expand people's access, including internet-based CBT. Rheumatology nurses are also being trained in the technique.
Mindfulness practices. Meditation, yoga, tai chi, acupuncture, and similar practices can help direct and distract the mind away from a focus on pain. These are powerful tools for reducing the impact of chronic discomfort, says Dr. Buxton.
Exercise. Regular physical activity relieves depression and anxiety about as well as many prescription antidepressants. In people with OA, RA, and other types of arthritis it also relieves pain and improves mobility. It's hard to get moving when you're pain, but the Arthritis Foundation has many good suggestions for people with arthritis to start.
Learn more about the emotion-pain connection on our Breaking the Pain Chain Toolkit.
Talking About PainChoose your words carefully to help your doctor treat you.
When you live with chronic pain, the only one who can know how much it hurts is you. Pain can be hard to describe because it's both invisible and personal. In a recent Arthritis Foundation survey, more than half of the respondents said they had trouble talking about their pain. If you can't put into words how much pain you're in or how it affects your life, your doctor can't prescribe the right treatment for you.
Silently enduring pain, day after day, can take a toll on your emotional health. "Pain plays a huge role in depression. Patients get very anxious if their pain isn't going away," says Thelma B. Wright, MD, medical director of the Pain Management Center at the University of Maryland Rehabilitation and Orthopedics Institute in Baltimore.
"If the pain is persisting, there's no reason to try to live with it," she says. "When you start to notice that the pain is becoming an everyday thing, you should see a doctor." Here's a guide to help you talk to your doctor about your pain so you can get the relief you need.
What Does the Pain Feel Like?
Is your pain burning, shooting, stabbing, dull or achy? Being as specific as possible about how it feels can help your doctor figure out what's wrong. "If I have a patient who tells me, 'In the morning, my back is so achy I can't get out of bed,' I know that's more arthritic pain," Dr. Wright says. "Whereas a patient who says, 'The pain shoots down my leg,' that's nerve pain."
Here are a few words you can use to describe the way your pain feels, and how your doctor might interpret them:
- Aching, dull: muscle strains, arthritis pain
- Shooting, electric, tingling, burning, pins-and-needles: nerve pain
- Sharp, stabbing: injuries such as a broken bone, muscle or ligament tear, or penetrating wound
- Throbbing: headache, abscess, gout
- Tightness: muscle spasm
Also describe exactly where you hurt - deep in your shoulder joint or in the muscles near the surface; under the kneecap or in the back of the knee; the outside of your hip or in your groin. Is the pain in only one spot, or does it travel? Does the pain remain steady, come and go, or only flare up when you move in a certain way?
How Much Does it Hurt?
In addition to getting a description of your pain, your doctor also needs to know the intensity. That's where the pain scale comes in. Your doctor will ask you to "rate" your pain on a scale of 0 to 10 - where 0 is pain-free and 10 is unimaginable pain. The doctor can use your score to help determine how much and what type of pain medicine you need.
How Does the Pain Affect Your Life?
Have you been skipping your morning jog because of the pain? Are you missing work? Can you barely get out of bed in the morning? Does the pain leave you so drained and depressed that you don't want to be around people? Just as important as the level of pain you feel is the impact it has on your life.
"Some patients come in the door with an eight on the pain scale, and they're functional. Other patients walk in with a three and they're disabled," Dr. Wright says. "Function is huge." Tell your doctor which activities you've had to adjust, and which ones you now avoid entirely because of your pain.
When Do You Hurt?
The timing of pain can help your doctor fine-tune your treatment. "If I notice that a patient has higher pain scores in the morning versus in the evening, I may tailor my medication management to that," Dr. Wright says. Keeping a journal can help you track when in the day your pain is at its worst.
What Helps/Worsens Your Pain?
Also note in your journal what you've tried to relieve the pain (rest, ice, heat, over-the-counter pain medicine). Did they ease the pain, have no effect or make it more intense?
With a good description of your pain, your doctor will have a better chance of getting you the relief you need. But even when your doctor knows the cause of your pain, treatment might not be a quick fix. "It's a trial and error process," says Dr. Wright. "You might go through several medications before you get the best combination."
If your pain has lasted more than three months and you haven't gotten relief from treatments prescribed by your primary care doctor or rheumatologist, keep working to find the right arthritis medicines, but also consider seeing a pain specialist. The American Academy of Pain Medicine offers a search tool to help you find a pain specialist in your area.