How Long Is the Flu Contagious?

Medically Reviewed by Shruthi N, MD on June 05, 2024
Written by WebMD Editorial Contributors
5 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.

About a week. Typically, you’re contagious from 1 day before you have any symptoms.

Is my flu still contagious?

You stay contagious for 5-7 days after you start feeling sick. Kids and people with weak immune systems may shed the virus even longer. The flu virus can be spread until symptoms disappear.

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. 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 any place where those droplets land -- such as a desk, counter, or doorknob -- and then touch your face. The virus can live on hard surfaces for up to 48 hours.

How to prevent spreading the flu

To stop the spread of flu germs:

  • Get a flu shot.
  • Cover your nose and mouth when you sneeze, preferably with a tissue.
  • Wash your hands immediately after with soap and water or use hand sanitizer with alcohol.
  • Clean and disinfect household surfaces such as countertops, doorknobs, faucets, toilets, light switches, and electronic devices.
  • Avoid interacting with others until you feel better or your fever is gone for 24 hours.
  • Don't touch your face, especially your eyes, nose or mouth.
  • Wear a mask.

How to prevent getting the flu after being exposed

Unlike the gradual symptoms of a cold, flu symptoms come on suddenly. Flu germs can spread up to 3 feet away through coughs and sneezes when someone has the flu. That's why it's important to wash your hands frequently, lathering your entire hand and scrubbing for 20 seconds or more. Use a paper towel to dry your hands and turn off the faucet. Disinfect frequently touched household surfaces to kill germs. Use a household cleaner that kills flu viruses or a mixture of 1/4 cup of bleach and a gallon of water to disinfect surfaces.

Other steps you can take:

  • If possible, keep the person with the flu in their own sick room.
  • Separate the sick person's personal items.
  • Avoid sharing pens, pencils, towels, bedclothes, food, or utensils with them.
  • Wear a mask when in the room with them.
  • Wear disposable gloves when handling dirty tissues or other items.
  • Wash contaminated sheets, towels, and clothes in hot water.
  • Eat a balanced diet, get plenty of rest, and exercise to boost your immune system.

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.

Fever is a definite sign. You should stay home for at least 24 hours after your temperature goes back down on its own — 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 medications 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.

How well flu vaccines work depends on how well they work against the flu viruses circulating in a given year. If there's a poor match between that year's viruses and the vaccine, then the vaccine's effectiveness is lower. If there's a good match, your chances of avoiding the flu rise. The CDC estimates that in flu seasons with well-matched vaccines, the risk of catching flu is lowered by 40%-60%.

The effectiveness of the flu vaccine also depends on your health and age. Still, studies have shown that flu vaccines:

  • Prevent millions of people from falling ill with the flu each year
  • Reduce the severity of the disease in those who do get sick
  • Prevent around 100,000 flu-related hospitalizations each year
  • Can be lifesaving for children aged 6 months to 17 years
  • Help vaccinated expectant mothers offer protection to infants in their first months of life, when they're too young for vaccines
  • Serve as a preventive tool if you have certain health conditions such as heart disease, diabetes or lung disease

Getting an annual flu vaccine also helps protect the vulnerable people around you.

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.

The best way to protect yourself and others against the flu is to get an annual flu vaccine. But you should also keep your distance from people who are sick, wash your hands often, and avoid touching your mouth, nose and eyes. If you have the flu, stay home until your symptoms are better and your fever stays normal for 24 hours without fever-reducing medicines.

How long are you contagious with the flu?

You can spread the flu before you feel ill, but you're typically most contagious during the first 3 days of your illness. People are usually contagious up to a week after they develop symptoms. Kids or people with weak immune systems can be contagious for longer.

How long is flu quarantine?

You should isolate from people until your symptoms go away and you've been fever-free for 24 hours without medicine.

Can you be around someone with the flu and not get it?

The flu is highly contagious, but washing your hands, covering coughs and sneezes, and disinfecting frequently touched surfaces may help prevent the spread. The best chance to avoid the flu is to get a yearly vaccine.

How long does it take to get over the flu?

Most people feel better in about a week. However, symptoms of cough and fatigue may last longer. If your fever returns with a worse cough, contact your doctor immediately.