How Long Is the Flu Contagious?

Medically Reviewed by Sabrina Felson, MD on December 11, 2022
2 min read

Doctors tell you to stay home when you have the flu so you don’t get other people sick. But how long do you have to shut yourself away? Here’s how to know when you can be out and about again.

How long can I spread it?

About a week. Typically, you’re contagious from 1 day before you have any symptoms. You stay that way for 5 to 7 days after you start feeling sick. Kids and people with weak immune systems may shed the virus even longer. The virus can be spread until symptoms disappear.

How do I spread it?

Most of the time, it’s through droplets in the air. Sick people sneeze or cough out beads of moisture that contain the flu virus. They can travel up to 6 feet. You’re exposed to the flu virus when you breathe the droplets in, or if they land in your mouth, nose, or eyes. You can also get it if you touch a place those droplets land -- like a desk, counter, or doorknob -- and then touch your face. The virus can live on hard surfaces for up to 48 hours.

When am I most contagious?

Some experts believe you’re most likely to spread the virus in the first 3 to 4 days. That’s because the more you cough and sneeze, the more droplets you shoot into the air and onto objects around you.

Is there a way to tell if I’m still contagious?

Fever is a definite sign. You should stay home for at least 24 hours after your temperature goes back down on its own. That means without the help of medicines.

Do flu medicines help stop the spread?

No. You can still make other people sick even if you’re taking antiviral mediations that treat the flu. The CDC recommends four FDA-approved drugs to treat the flu: baloxavir marboxil (Xofluza), oseltamivir (Tamiflu), peramivir (Rapivab), and zanamivir (Relenza). These drugs could shorten the time that you’re sick. And they might shorten the length of time that you can spread the flu.

The Bottom Line:

When it comes to the flu, an ounce of prevention really is worth a pound of cure. Listen to your doctor: Stay away from people when you’re sick, even if you start to feel better. It’s the only way not to spread the flu. And remember you and your family should get the annual flu vaccine.