Flu (Influenza)


Mother checking daughter's temperature

Influenza (flu) is a common contagious viral respiratory illness that infects the nose, throat, and lungs. Flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. Flu illness can vary from mild to severe. When severe, flu can result in hospitalization and even death. Some people are more likely to suffer serious flu complications, including older adults, pregnant women, young children and people with certain chronic health conditions. CDC recommends that everyone 6 months and older get an annual flu vaccine. Flu vaccination can prevent flu illnesses and its potentially serious complications. While flu vaccination varies in how well it works, an annual flu vaccination is the best way to protect against flu. However, there is a second line of defense for treatment of flu. Influenza antiviral drugs are prescription medications that reduce severity and duration of illness and also may prevent serious flu complications. CDC recommends influenza antiviral treatment for people who are very sick with flu and people with flu symptoms who are at high risk of developing serious flu complications.


Key Facts

  • The severity of flu seasons can differ substantially from season to season.
  • You may be able to spread flu to someone else before you know you are sick, as well as while you are sick.
  • Hundreds of thousands of people are hospitalized because of flu each year.
  • People with certain long-term health conditions, like asthma or diabetes, are at high risk of serious flu complications.
  • Take 3 steps to fight flu: get vaccinated, take everyday preventive actions, and take antiviral medicines if prescribed.


Grandfather with granddaughter

Are you at high risk?

Certain people are at a greater risk of developing serious flu complications. These groups of people include: children younger than 5, adults 65 years of age or older, pregnant women, and people with certain chronic health conditions.

In this infographic, learn how flu vaccination during the 2015-2016 flu season benefitted the U.S. population.

Take Three Actions to Fight Flu

In this infographic, learn how to fight flu by getting vaccinated, taking every preventive actions, and taking antiviral medicines if prescribed.

Screenshot of Prevent Flu! video play video

Prevent Flu!

Screen from the Danger of Flu video play video

Protect Your Family From the Potential Danger of Flu

Take 3: Seasonal Flu play video

Take 3: Seasonal Flu

Prevention Tips

  • An annual flu vaccination is the best way currently available to reduce the risk from flu and its potentially serious complications. As long as flu viruses are spreading, you can still benefit from a flu vaccine.
  • Avoid people who are sick.
  • Avoid touching your eyes, nose, or mouth. Though less common, flu viruses can spread when a person touches something that is contaminated with flu viruses and then touches their eyes, nose, or mouth.
  • Wash your hands regularly. If soap and water are not available, use an alcohol-based hand rub.
  • People at high risk of serious flu complications who develop flu symptoms should consult a health care provider. They may prescribe influenza antiviral drugs, which can lessen the severity of your illness, shorten the amount of time you are sick and prevent serious flu complications.

More at CDC.gov

Page last reviewed: October 28, 2019