Cold & Flu Health Center
Understanding Common Cold -- Basics
Sneezing, scratchy throat, runny nose -- everyone knows the first miserable signs of a common cold. But what is a common cold really? What causes you to catch colds frequently while your best friend stays well? And more importantly, how can you prevent getting a cold this season? Here are some common cold basics to help you protect yourself and your family from getting sick.
What Is a Common Cold?
The common cold is a group of symptoms in the upper respiratory tract caused by a large number of different viruses. Although more than 200 viruses can cause the common cold, the perpetrator is usually the rhinovirus, which is to blame for causing 10% to 40% of colds. Also, the coronaviruses cause about 20% of colds and the respiratory syncytial virus (RSV) causes 10% of colds.
The rhinovirus (or other cold virus) enters your body through your nose or mouth and is easily spread when you touch someone or touch common objects (the computer keyboard or mouse, the telephone receiver, a doorknob, or eating utensils). If you aren't cautious about hand washing, you can spread the common cold to family, friends, co-workers, and people you've never met at a restaurant or the supermarket.
What Causes a Common Cold?
While getting chilled or wet is not a cause of common colds, there are factors that make you more susceptible to catching a cold virus. For example, you are more likely to catch a common cold if you are excessively fatigued, have emotional distress, or have allergies with nose and throat symptoms.
For more detail, see WebMD's article on Common Cold Causes.
How a Common Cold Starts
With a common cold, you catch the virus from another person who is infected with the virus. This usually happens by touching a surface contaminated with cold germs and then touching your nose or mouth. You can also catch a cold by encountering secretions someone has sneezed into the air.
A cold begins when a cold virus attaches to the lining of your nose or throat. Your immune system sends white blood cells out to attack this germ. Unless you've encountered that exact strain of the virus before, the initial attack fails and your body sends in reinforcements. Your nose and throat get inflamed and produce a lot of mucus. With so much of your body's energy directed at fighting the cold virus, you're left feeling tired and miserable.
Although the common cold is usually mild, it is a leading cause of doctor visits and missed days from school and work. According to the CDC, 22 million school days are lost annually in the U.S. because of the common cold. Some estimates state that Americans suffer 1 billion colds annually.
WebMD Medical Reference
Cold Guide
