Colds are caused by viruses. More than 200 types of virus can cause a cold. Those most responsible for colds belong to one of two groups:
- rhinoviruses
- coronaviruses
Because a number of viruses can cause a cold, it's possible to have several colds, one after the other, as each one is caused by a different virus.
What do colds do to the body?
The viruses that cause a cold attack the lining of the nose and throat, inflaming these areas. As they become inflamed, they begin to produce more mucus, resulting in a runny nose and sneezing.
How is a cold spread?
Colds 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.
