This Version Posted: December 19, 2019

Influenza (the flu) is a serious respiratory illness caused by a virus. People of any age can get the flu, and illness usually lasts five to 10 days, sometimes longer in older adults and in people with chronic diseases. Most people who get the flu are ill for only a few days. However, some people can become very ill, possibly developing complications and requiring hospitalization.

The influenza virus spreads mainly from person to person through coughing or sneezing. People can become infected by touching objects or surfaces with flu viruses on them and then touching their eyes, mouth or nose.

Symptoms include:
  • fever
  • cough
  • runny or stuffy nose
  • sore throat
  • headache
  • muscle aches
  • extreme weakness and fatigue

The best way to prevent the flu is to be immunized every year. The flu shot is a safe and effective way to protect you and your family from becoming ill with the flu. The flu shot strengthens your immune system to build up antibodies against the virus. It can take up to two weeks for antibodies to build up after you get the flu shot.