The flu is an illness that spreads easily from person to person. It affects your lungs, throat, and nose. Some people get a little sick, while others can get very sick. The flu can be dangerous for babies, older people, and people who have certain health conditions.
In the U.S., most people get the flu between December and February. But flu season can start in the fall and go all the way through spring.
Flu symptoms start fast and can include:
The flu tends to come on suddenly. It feels much worse than a cold. You may experience:
These symptoms can last a week or more. Colds usually develop slowly. They cause milder symptoms like a stuffy nose or sore throat.
Learn more about flu symptoms.
The flu spreads in two main ways. It can spread through tiny drops in the air. These drops come out when a sick person talks, coughs, or sneezes. You can also catch the flu by touching surfaces with flu germs on them and then touching your eyes, nose, or mouth.
People are most contagious during the first three to four days after symptoms begin. But some can spread the virus even before symptoms start.
Anyone can get the flu. However, some people are more likely to develop serious complications. These can include:
If you're in one of these groups, it’s important to take extra steps to stay safe and healthy during flu season.
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