According to the Centers for Disease Control and Prevention (CDC), 22 million school days are lost annually in the United States due to the common cold. According to some estimates, in the course of a year, people in the United States suffer 1 billion colds. The virus is most often transmitted through contact with infected surfaces or inhaling cold germs from an infected person. Symptoms usually appear two or three days after becoming infected and include sore throat, coughing, runny nose, and fever.
(Click Common Cold to learn more, including other symptoms, treatment options, how infection can be prevented, and more.)