Colds (aka the common cold) are illnesses caused by viruses that affect the upper respiratory tract (throat, nose, sinuses and ears). It could also be called a URI, or upper respiratory infection. The flu (influenza) is a more severe version that can sometimes affect the lower respiratory tract (lungs) as well. Both tend to occur more in the fall, winter and early spring in the north. Stress, poor nutrition and lack of sleep increase the risk for catching these infections. Hand-washing is the best way to reduce the spread of these infections.
There are more than 200 different cold viruses. Rhinovirus is the most common. Symptoms of a cold are runny nose, sore throat, sneezing, congestion, cough and chills. In infants, the only symptom might be a fever. In children, up to 20 percent of colds will also affect the ears and can give symptoms of ear infections.
Although adults usually only get two to three colds a year (sometimes more if there are underlying illnesses like nasal allergies), children typically get eight to 12 colds per year. The colds can be as brief as a few days or as long as a few weeks.
Colds are a large burden on society in terms of missed days at work and school. In the U.S., between 75 million and 100 million people see their doctors with such symptoms, and about 150 million days of work are missed.
There is no cure for the common cold. Unlike the flu, there are no vaccines against colds. The treatments are directed at symptoms, which will be gone once the body is done fighting off the infection.
The flu is a more severe illness caused by the Influenza A or B viruses. The symptoms involve the upper respiratory tract, but can also affect the lower respiratory tract. Typical flu symptoms are abrupt onset of fever, aches, headache, sore throat and a dry cough. Children may also have additional symptoms of ear infections, nausea and vomiting.
Symptoms last five to eight days, but can last longer and remain contagious longer in children and in those who are immunocompromised.
According to the World Health Organization, about 5 to 10 percent of adults and 20 to 30 percent of children get the flu worldwide. The flu is responsible for many hospitalizations and deaths every year, especially in chronically ill patients, young children and elderly patients.
The flu can be “treated” with antiviral medication, but they only shorten the duration of the flu by a day on average.
Vaccination is available against influenza for anyone over the age of 6 months (unless there is an allergy or contraindication). Since the flu virus mutates so easily and often and the vaccines are made on best predictions of what types of virus will be coming, the vaccination may not always be effective. However, most vaccinated people who still catch the flu usually get a milder case of the flu than if they hadn’t been vaccinated.