Common cold

The various viral infections of the respiratory tract referred to as colds, and their complications, are responsible for much discomfort and disability, including work absenteeism and vast expenditures for drugs and medical services.

Colds are caused by many different kinds of viruses. About 30 to 50% are caused by viruses of the rhinovirus family, which includes more than 100 known kinds.

There are many mistaken beliefs about the way colds are caught and cured. In one survey (2001), investigators found that 60% of parents erroneously believed that some colds were caused by bacteria and nearly half erroneously believed viral illnesses such as colds, bronchitis and green mucous should be treated with antibiotics. 46% thought colds could be caused by not wearing enough clothes, 57% they could be caused by cold weather, and 37% they could be caused by going outside with wet hair. Colds are more easily transmitted through contact with the nose and eyes more often than through the mouth. However, 90% of the parents focused preventive measures on issues such as sharing drinks or utensils, or kissing someone with a cold, while only three-quarters correctly thought shaking hands was a key culprit for catching a cold. 50% of the parents thought antibacterial soaps are an effective mechanism, but these would be no more effective against catching a cold virus than washing with simply soap and water.

Colds are responsible for more lost work days than any other viral infection. On average adults have two colds a year and children five or six. And it occurs in wet and cold weather. People with impaired or weak immunity systems, such as people with AIDS, the very young and the very old are at particular risk. Smokers tend to get more frequent and severe colds as a result of damaged lungs. Babies may be at risk of death because their narrow airways are easily plugged by secretions pouring out in response to infection. Introverted people have more colds and spread more viruses when they are infectious. As an indication, the market for cold remedies (including inhalants and rubs) in the UK in 1986 was £34 million.