Influenza, commonly known as the flu, is a contagious respiratory tract infection caused by the influenza virus. Symptoms of influenza generally include fever, cough, sore throat, muscle aches, headache, or fatigue. Influenza can cause mild to severe illness, and at times can lead to death.
During most influenza seasons, typically from November to April, between 10 percent and 20 percent of the population is infected with influenza. More than 200,000 people are hospitalized with influenza each year in the U.S. Certain groups of people, including older adults, young children, pregnant women, and people with certain health conditions, are at higher risk for serious complications from influenza illness.
The best way to avoid getting and spreading the flu is by getting vaccinated each year. Get more information on influenza prevention, treatment, and find out where to get a flu shot