How Long Does the Flu Last?

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Your nose feels a bit stuffy. Then you cough—a dry cough that makes your head ache, until you realize it’s not so much a headache as it is a headache in your stomach. Then you notice your arms and legs feel weird—restless, achy—and you just can’t seem to get comfortable. But if you know the symptoms of influenza, you’re probably beginning to realize what’s happening,  and your first question is probably going to be something along the lines of: How long will the suffering last?

Read on for the answer with input from influenza experts Susan Besser, MD, who practices primary care and family medicine at Mercy Medical Center in Baltimore, and Megha Tewari, MD, who practices family medicine at the Memorial Hermann Medical Group Imperial Oaks in Houston, Texas.

What is influenza?

Influenza is a viral infection that’s highly contagious because it’s transmitted both through the air (think: coughing, sneezing, or talking) and on surfaces (for instance, that door knob you just touched). If you’re exposed to the virus, there’s about a 50/50 chance you’ll get sick, according to Dr. Tewari, although if you get the vaccine, your chances of staying healthy are higher. If the virus does take hold, flu symptoms tend to set in within two to seven days, coming on suddenly and with intensity. (Find out how long colds last.)

How long does the flu last?

Generally, it takes only a few days for the worst of it to resolve, says Dr. Besser, and by the “worst of it,” she’s referring to the headache, body aches, and gastrointestinal symptoms such as nausea, vomiting and/or diarrhea. (Gastrointestinal symptoms are unusual in adults with influenza, so if those are your main symptoms you may have another germ, like norovirus.) However, it could take at least two weeks for all the symptoms to resolve. Dr. Tewari breaks it down by symptom as follows:

• Stomach issues: one to three days
• Headache: one to three days
• Fever: three to seven days
• Body aches: three to five days
• Fatigue: one to two weeks
• Coughing: one to two weeks

(Do these symptoms sound familiar? Here’s how to tell the difference between coronavirus and flu symptoms.)

“Some patients may recover more quickly than others,” says Dr. Besser. Those who’ve had a flu shot are likely to recover faster. “If a person has an underlying illness (such as emphysema or other chronic illness), that person may take longer to recover.” Drs. Besser and Tewari agree that you should be able to return to work once you’ve been fever-free (without using fever-reducing medications) for 24 hours. Staying home isn’t just about taking care of yourself, either. It’s about keeping others from getting sick, which is most likely to happen during the first 24 to 48 hours after the symptoms kick in. Young, elderly, and those with certain underlying conditions are also more likely to develop complications of the flu and have a severe course.

Next, here’s how doctors avoid getting colds and influenza, and find out the surprising ways you’re making your cold or flu worse.