Harvard Medical School Guides
A Harvard Medical School Guide: Cold and Flu
Ah-choo! You're bound to hear that sound — along with sniffling, coughing, and nose-blowing — every winter when cold-and-flu season sprinkles its misery on just about everyone. Up to 20% of Americans get the flu every year, and Americans suffer one billion colds. Children get colds and the flu more often than adults. Some kids get as many as 12 colds a year, while adults average two to four.