- Last Updated: 19 April 2018 19 April 2018
Influenza (the flu) is an infection of the nose, throat, and lungs caused by influenza viruses. There are many different influenza viruses that are constantly changing. Flu viruses cause illness, and hospital stays in the United States each year.
The flu can be very dangerous for children. Each year about 20,000 children younger than 5 years old are hospitalized from flu complications, like pneumonia. This leaves parents with question so please read this pamphlet put out by the U.S. Department of Health and Human Services to help answer some of those questions.