What's the Difference Between the Flu and COVID-19?

The flu and COVID-19 are both contagious respiratory illnesses with similar symptoms, but they are caused by two different viruses. Both are serious enough that they can result in severe illness and hospitalization, but they require different methods of both treatment and prevention.

Because the symptoms of the two viruses are so similar, it can be hard to differentiate between them based on symptoms alone. Diagnostic testing can help determine if you are sick with flu or COVID-19.

For more information on flu, please read the CDC’s Frequently Asked Influenza Questions for the 2022-2023 Season.

Frequently Asked Questions

While the flu and COVID-19 share many symptoms, there are some key differences. View our flu and COVID-19 comparison chart to better understand the symptoms for each.

Learn more about flu and COVID-19 symptoms on the CDC website.

The majority of people infected with flu or COVID-19 have fairly mild illness that does not require medical care. However, treatment differs in cases of severe illness.

Severe flu illness – or flu symptoms in those considered high-risk from other health conditions – can be treated with prescription antiviral medication. Please contact your doctor as soon as you begin experiencing symptoms to determine the proper course of treatment for your illness.

There is currently no known proven treatment for COVID-19. In cases of severe illness, certain COVID symptoms, such as difficulty breathing, can be treated directly through supportive care, such as oxygen and IV fluids.

Yes, you can have the flu – or other respiratory illnesses – and COVID-19 at the same time. Health experts are still studying how common this is. Some of the symptoms of flu and COVID-19 are similar, making it hard to tell the difference between them based on symptoms alone. Diagnostic testing can help determine if you are sick with flu or COVID-19. If you receive a flu test, you may also be tested for COVID-19 at the same time.

Some of those at increased risk for serious flu and COVID-19 complications, for whom extra precaution is needed, include:

  • Adults 65 and older
  • People of any age with certain chronic conditions, such as asthma, diabetes, chronic kidney disease or heart disease
  • People with weakened immune systems
  • People with a BMI of 40 or higher (or, in the case of COVID-19 specifically, 30 or higher)
  • Pregnant or breastfeeding women

Learn more about the risk factors for flu and COVID-19.

No, the flu shot does not provide protection against any virus other than the flu. However, it is important that you get your flu shot this year to help reduce your risk of flu-related illness. A flu vaccination can help keep you, your family and friends, and your community healthy, and help reduce the burden on our health care system and workers who remain very busy responding to COVID-19.

No, there is no evidence that the flu shot will increase your risk of getting COVID-19.

Evidence shows that getting a flu shot is a critical step in protecting yourself and your family during flu season. Please follow CDC guidelines, including wearing a mask, to help protect you against COVID-19 while you are getting your flu shot.


Yes. It is safe to receive vaccinations for both flu and COVID-19 during the same visit. There is no need to wait to receive these vaccinations on different days.