Colds and flu

A cold is an infection that affects the upper respiratory tract. That's the nose, throat, sinuses (small spaces in the skull behind the eyes and nose), trachea (the main airway that goes to the lungs), larynx (voice box) and bronchial tubes (the airways in the lungs).

Colds are caused by viruses and can be spread in several ways. If you have a cold and you sneeze, cough or speak, tiny droplets of fluid containing the cold virus are launched into the air. If these are breathed in by someone else then they may become infected.

Colds can also spread through direct and indirect contact. If you have a cold and you touch your nose or eyes and then touch someone else, you may pass the virus on to them. Alternatively, if you touch an object such as a door handle or telephone, the virus may be transferred to the object. If someone touches the object a short time later and then touches their mouth, nose or eyes, they may become infected.

In this section

The symptoms of a cold usually begin two to three days after you become infected, and last for two to 14 days. Most people recover from a cold within a week. You're most contagious when you have the sneezing, runny nose and cough that are the first signs of a cold developing.

Colds are very common. They occur mainly during the winter months, although cold weather itself is not a cause of colds.

Children tend to have more colds than adults. This is because adults have built up immunity against some of the viruses that cause colds. On average, adults have between two and four colds a year, while children may have as many as eight or 10.

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