What to do About the Flu?

Silvana Barbosa, Emma Roy, and Kobi Khong, National Center for Health Research

What is the Flu

Influenza, also known as the flu, is a very contagious respiratory virus that can cause mild to severe illness. The flu usually comes on suddenly and symptoms may include runny or stuffy nose, fever, cough, sore throat, headaches, fatigue, and body aches. Although most people recover quickly, the flu can be fatal, especially for young children, elderly adults, and individuals with a compromised immune system. Most people who had to go to the hospital for flu-related reasons were aged 65 and older.

The specific strains of virus that cause the seasonal flu can be different every year, which is why we need to get annual flu shots instead of a one-time vaccination. Public health experts keep a close watch on the flu viruses from previous years and ones moving through animal populations to predict which strains are likely to cause infection during flu season. If you want to learn more about the flu vaccine you can check out our article on “If you should get the flu vaccine.”

As a result of the masks, social distancing, and other restrictions due to the COVID-19 pandemic, the proportion of people diagnosed with flu last year was unusually low all over the world. Some experts think this could result in less immunity and a more severe flu seasons in 2022 and the following years.  During the beginning of the 2022-2023 flu season, from October 1 to November 5 of 2022, the U.S. Centers for Disease Control and Prevention

(CDC) has estimated 2.8-6.6 million illnesses, 23,000-48,000 hospitalizations, and 1.300-3,600 deaths from the influenza virus.1

When is the Flu Contagious?

The flu is most contagious during the first three to four days of the illness. However, healthy adults who have contracted the flu can begin to infect others 24 hours before symptoms develop. This means that you may pass the flu to someone else before you even know you are sick. Individuals with the flu are typically contagious for up to 7 days after becoming sick. Children and some people with weakened immune systems may spread the virus to others for more than 7 days.2

Scientists suspect that the flu virus spreads through tiny droplets of fluid that become airborne after coughing, sneezing, or talking. These droplets can then land in the mouths or noses of people nearby. People with the flu can spread the virus to others who are up to 6 feet away. The flu may also spread if a person touches a surface or object that has the flu virus on it and then touches their own mouth, nose, or eyes, although this is less likely.2

If you have the flu, it is important to stay home and avoid contact with other people unless you are seeking medical help. The CDC recommends you stay home for at least 24 hours after your fever is gone without the use of fever-reducing medicines. If you leave home while you are sick, wear a face mask to prevent the spread of the flu and wash your hands often.3

How Long Does the Flu Last?

The flu is typically a short-term illness that lasts roughly 3 to 7 days. On average, people who received a flu shot usually experience less severe symptoms for fewer days, but flu vaccines are more effective some years than others.4

People at high risk of developing flu-related complications include individuals with underlying medical conditions, children younger than age 5, adults aged 65 and older, pregnant women, and residents of long-term care facilities. These adults and children are more likely to develop complications such as pneumonia, bronchitis, and sinus infections. They may also experience more severe flu symptoms that last longer than 7 days. For a full list of the types of people at highest risk of potential complications, please see here.

Some flu patients are prescribed antiviral medications such as Tamiflu. Roche, the company that makes Tamiflu, claims that Tamiflu reduces the number of patients who have serious complications from the flu, such as pneumonia or hospitalization. However, Tamiflu has some serious risks, is only effective if started within 48 hours of feeling sick, and even if started that early, it has little benefit, speeding up recovery by just one day. Study results are contradictory regarding whether it reduces the severity of the flu, and it can have unpleasant or serious side effects.  To read more about Tamiflu, see To Tamiflu or Not to Tamiflu?

What Steps Can I Take to Prevent the Flu?

To protect yourself during flu season, avoid close contact with people who might have the flu, stay home when you might have the flu, wash your hands often, and avoid touching your eyes, nose, and mouth.

In addition, the CDC recommends everyone 6 months of age and older get a flu vaccine every season, preferably before the end of October. The seasonal flu vaccine protects against the flu virus strains that experts predicted are likely to be most common during the upcoming season.  These predictions are more accurate some years than others. Flu vaccines cause the body to develop antibodies against the virus, to protect against infection.

Worried about getting the flu? Here are recommendations from the CDC on how to stay healthy during flu season:5

  1. Avoid close contact. Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.
  2. Stay home when you are sick. If possible, stay home from work, school, and errands when you are sick. You will help prevent others from catching your illness.
  3. Cover your mouth and nose when coughing or sneezing. Whenever possible, cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick. If you use your hand to cover your mouth, wash your hands to prevent you from spreading the virus.
  4. Clean your hands. Washing your hands often will help protect you from germs. If soap and water are not available, use an alcohol-based hand rub.
  5. Avoid touching your eyes, nose, or mouth. Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
  6. Practice other good health habits. Clean and disinfect frequently touched surfaces at home, work, or school, especially when someone is ill. Many common household products can kill the flu virus, such as chlorine, hydrogen peroxide, and alcohol. Antibacterial products will not kill viruses. Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids, and eat plenty of fruits and vegetables.

Symptoms to Watch Out For

As noted above, the flu can be life-threatening for individuals with underlying medical conditions, very young children, and older people. If a family member fits any of these categories and begins to have flu-like symptoms, they should not delay seeing a doctor if symptoms are getting worse rather than better.

For children with the flu, watch out for dehydration (if the child refuses to drink); blue/gray lips, skin, or fingernails; rapid breathing; extreme sleepiness, irritability, or confusion. These symptoms mean the child needs immediate medical attention. Some flu viruses can cause more severe symptoms such as seizures in children.3

The symptoms to watch out for in adults include chest pain, shortness of breath, sudden dizziness, and confusion. And if a person with the flu seems to be recovering and then takes a turn for the worse, developing a fever (or a recurrence of fever) or a more pronounced and painful cough with phlegm, he or she should get medical attention because another infection may be present.3

I’m Sick! What Should I Do?

If you think you’re getting sick with the flu, these tips can help you stay healthy and keep those around you safe as well.3

  1. Drink lots of clear liquids like water to prevent dehydration.
  2. Treat a fever with cool washcloth compresses, a lukewarm bath, or over-the-counter fever reducers.
  3. Treat a cough with a humidifier or over-the-counter cough medicines.
  4. If you are vomiting or have diarrhea, eat plain foods like crackers and drink lots of water.
  5. Stay home and socially isolate yourself from loved ones, people you interact with, and those who may have weakened immune systems to keep them from catching the flu.
  6. If your symptoms worsen and become very severe, call your doctor.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.


  1. Centers for Disease Control and Prevention. (2022, November 10). Preliminary In-Season 2021-2022 Flu Burden Estimates. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm
  2. Centers for Disease Control and Prevention (2022, September 20). How Flu Spreads. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/about/disease/spread.htm
  3. Flu: What To Do If You Get Sick | CDC. (n.d.). Retrieved November 17, 2022, from https://www.cdc.gov/flu/treatment/takingcare.htm
  4. How long does the flu last? (2016, December 8). Harvard Health. https://www.health.harvard.edu/staying-healthy/how-long-does-the-flu-last
  5. Centers for Disease Control and Prevention. (2021, August 26). Practice Good Health Habits. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/prevent/actions-prevent-flu.htm