Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs.
Some people—such as older adults, young children, and people with certain health conditions—are at higher risk of serious flu complications. Learn more about the CDC guidance for people at increased risk of flu complications.
There are two main types of influenza (flu) viruses: Types A and B. The influenza A and B viruses that routinely spread in people are responsible for seasonal flu epidemics each year. Explore the CDC's current flu season information to learn more.
Actions To Help Prevent the Flu
Get Vaccinated
- A yearly flu vaccine is the first and most important step in protecting against flu viruses
Stop the Spread of Germs
- Take everyday actions to help stop the spread of germs. Cover coughs and sneezes, stay home when you’re sick, and wash your hand frequently
Get Treatment
- If you become sick and are at increased risk for serious complications from flu, contact your doctor right away to discuss the benefits of antiviral medications that can be used to treat flu illness.
