The cold is a common infection of the upper respiratory tract. Although many people think you can catch a cold by not dressing warmly enough in the winter and being exposed to chilly weather, it's a myth. The real culprit is one of more than 200 viruses.
The common cold is spread when you inhale virus particles from an infected person's sneeze, cough, speech, or loose particles from when they wipe their nose. You can also pick up the virus by touching a contaminated surface that an infected individual has touched. Common areas include doorknobs, telephones, children's toys, and towels. Rhinoviruses (which cause the most colds) can live for up to three hours on hard surfaces and hands.
Some other common cold culprits have been singled out, such as the respiratory syncytial virus. Still, others have yet to be identified by modern science.
In the United States, colds are more common in the fall and winter. This is mostly due to factors such as the start of the school year and the tendency for people to remain indoors. Inside, air tends to be drier. Dry air dries up the nasal passages, which can lead to infection. Humidity levels also tend to be lower in colder weather. Cold viruses are better able to survive in low humidity conditions.