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Flu (Influenza): Symptoms and How Long It Lasts

Find out how to treat your flu symptoms to feel better faster
A frowning man wearing a purple shirt and blue scarf. Yellow viruses and shiver lines surround his head, and there is a blue drop of sweat on his forehead.
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Care Plan


First steps to consider

  • You can treat flu symptoms at home
  • Taking OTC pain relievers and other medications can help symptoms. Rest and drink fluids.
See home treatments

When you may need a provider

  • Symptoms worsen or fever doesn’t go down when taking fever-reducers.
  • Any young children, older adults, and people with chronic conditions who have flu symptoms.
See care providers

Emergency Care

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Call 911 or go to the ER if you have any of the following symptoms:

  • Difficulty breathing
  • Chest pain
  • Lasting dizziness
  • Severe weakness or muscle pain
  • A chronic condition you have is getting worse

What it is

Pro Tip

Flu can be deadly, but it can also be preventable. Everyone over the age of 6 months should get some form of the flu vaccine every year. Even if you have had the flu or the vaccine before. Neither gives life-long immunity. - Dr. Chandra Manuelpillai

Influenza—or the “flu”—is a common contagious disease caused by a virus. Generally, you have a fever, sore throat, muscle pain, and feel tired.

The most common time to get the flu is October to May, but peak flu season is December to February. You can get the flu more than once, even in the same year.

The best way to prevent the flu and stop its spread is the flu shot. It doesn’t always completely protect you from the flu, but if you do get it, symptoms should be milder.

Also, avoid contact with anyone who you know is sick. And maintain good hygiene, like frequent handwashing.

Most common flu symptoms

Often, people have a high fever, cough, headache, sore throat, and chills. You may also have a runny nose, muscle aches, and feel tired.

The flu may be confused with the COVID-19 virus (coronavirus). One key difference is that the flu tends to come on suddenly, while COVID-19 tends to develop and worsen over several days.

Both viruses can cause similar symptoms including fever, chills, body aches, fatigue, cough, headache, and sore throat. But the coronavirus is more likely to cause coughing and shortness of breath. (Though if the flu leads to pneumonia, it will also cause shortness of breath.) The coronavirus can also cause a loss of taste or smell.

Main symptoms of the flu

  • Feeling tired
  • Fever
  • Cough
  • Muscle aches throughout your body
  • Headache, often behind your eyes

Other symptoms you may have

  • Sore throat
  • Stuffy nose

Gastrointestinal symptoms including nausea, vomiting, and diarrhea—more common in young children

How long does the flu last?

In most people, symptoms will peak 2 to 4 days after they start. And it can be 1 to 2 weeks before you feel completely better.

Follow up with your doctor if your symptoms get worse or you develop new symptoms.

What causes influenza?

The flu is caused by the spread of the influenza virus from an infected person. Tiny droplets that contain virus are breathed out by one person and then inhaled by another. It could happen after a cough or sneeze.

When infected, you are contagious one day before you experience any symptoms until about five days after symptoms begin.

Pro Tip

Discuss with your doctor your risks of developing the flu, which vaccine is best for you, and ways to prevent catching it. Also, what are the signs and symptoms you should look out for and when to go to your doctor’s office versus an urgent care or emergency department. - Dr. Manuelpillai

Treatment for the flu

If you are in a high-risk group, you may be given an antiviral medication, which can reduce the symptoms by 1 to 2 days and reduce your risk of developing complications. The following treatments can ease your symptoms.

  • Drink plenty of fluids.
  • Rest and sleep.
  • Avoid alcohol and smoking, which can lower your resistance to infections.
  • You can also take over-the-counter medications to help with symptoms.


The following medications may relieve your symptoms. They will not shorten how long you have the flu.

  • Acetaminophen: Decreases fever and provides pain relief.
  • Ibuprofen or naproxen: Pain relief and decrease fever.
  • Phenylephrine or pseudoephedrine: Clears stuffy noses.
  • Dextromethorphan-guaifenesin: Reduces cough and mucus
  • Prescription antiviral drugs. These can shorten how long the flu lasts, usually by 1 to 2 days. They don’t make your symptoms less severe and are usually not given to healthy people. (They can have side effects like nausea, vomiting, and diarrhea). You also must take them within the first 48 hours of when your symptoms started. These medications include Oseltamivir (Tamiflu) and Zanamivir (Relenza)

Do not give aspirin to children younger than 18 years old. It could lead to death (through a reaction called Reye’s syndrome). Always check with your pediatrician before giving any medications to a child.

Ready to treat your flu?

We show you only the best treatments for your condition and symptoms—all vetted by our medical team. And when you’re not sure what’s wrong, Buoy can guide you in the right direction.See all treatment options
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What makes you more likely to have severe flu symptoms

  • Age 65 or older or under 5 years old
  • Being pregnant
  • Have asthma, diabetes, heart disease, or are obese
  • Immunocompromised (including from HIV, chemotherapy, and organ transplants)
  • Live in a nursing home or long-term facilities.

Is influenza serious?

Most people recover on their own without complications. If you think you have the flu, contact your doctor, who may want to test you for the flu.

If you are at risk of severe flu symptoms, see your doctor that day or go to urgent care. They may prescribe an antiviral medication to reduce the number of days you are sick and the risk of complications.

If you have severe symptoms such as dizziness, increased heart rate, severe weakness, severe vomiting, or difficulty breathing, go to the emergency room.

Pro Tip

Some people who receive the shot will develop mild body aches and fever from the immune response. This is not the flu, but rather your body appropriately reacting to the vaccine. - Dr. Manuelpillai

Flu prevention tips

Get your flu shot (influenza vaccine) every year. It should be available from your doctor, urgent care, clinics, pharmacies, and possibly at your workplace.

There is no life-long immunity from having the flu—you can get the flu virus even if you’ve had it before.

Because the flu virus changes from year to year, the vaccine also has different influenza strains each year. The vaccine is made based on which flu strains are predicted to be most common.

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The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.
Dr. Manuelpillai is a board-certified Emergency Medicine physician. She received her undergraduate degree in Health Science Studies from Quinnipiac University (2002). She then went on to graduated from Rosalind Franklin University of Medicine and Sciences/The Chicago Medical School (2007) where she served on the Executive Student Council, as well as was the alternate delegate to the AMA/ISMS-MSS G...
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