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Factors that put you at high risk for severe COVID-19

Learn who is at high risk for severe COVID-19 and what steps you can take to help reduce your risk.

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Key takeaways

As COVID-19 becomes a part of our ongoing public health landscape, it still poses a serious threat—especially for certain groups of people.

If you or someone you care for is considered “high risk,” that means there’s a greater chance of developing severe outcomes if infected. It’s estimated that about 75% of U.S. adults have at least one risk factor that puts them at high risk.

Understand your risk and take action if you do get sick can go a long way in helping to prevent COVID-19 from progressing into serious illness.

Who is considered high risk for severe COVID-19?

COVID-19 doesn’t affect everyone the same way. While some people experience no symptoms, mild symptoms, or recover quickly, others face a much higher chance of serious illness.

The following groups of people are considered at risk for developing severe COVID-19:

To find out if you are at risk of severe COVID-19, take a risk assessment.

If you fall into one of these categories, it’s important to take extra precautions against respiratory virus symptoms that aren't better explained by another cause. Learn more about what to ask your healthcare provider if you have COVID-19.

What is severe COVID-19?

Severe COVID-19 is not defined by one symptom, but rather how serious the illness becomes. According to the Centers for Disease Control and Prevention (CDC), severe COVID-19 is often associated with outcomes such as:

Warning signs to watch for include:

It’s important to note that severe illness doesn’t always happen immediately. Symptoms can worsen over several days, which is why early monitoring and medical attention are critical—especially for those in high-risk groups.

COVID-19 doesn’t affect everyone the same way. Some people experience no symptoms, mild symptoms, or recover quickly, while others face a much higher chance of serious illness.

How to help lower your risk of getting severe COVID-19

The good news is that there are ways to help reduce your risk of getting COVID-19 or developing severe illness if you do get infected.

What to do if you test positive for COVID-19

If you’re high risk and test positive for COVID-19, don’t wait to act. Talk to your doctor right away. There are prescription medications but they must be started early, so reach out to your healthcare provider as soon as possible.

The CDC recommends staying home and away from others if you test positive. When, for at least 24 hours, your symptoms are getting better and you haven’t had a fever and are not taking fever-reducing medicine, take added precaution over the next 5 days as you get back to your normal activities. These include taking additional steps for cleaner air, practicing good hygiene, wearing a well-fitting mask, physical distancing, and/or testing when you plan to be around other people indoors.

Taking charge of your COVID-19 risk

Many people don’t realize they’re at increased risk for severe COVID-19. But understanding your personal risk—and what you can do about it—can make a difference. Knowledge is power, and taking steps like staying up to date on vaccination and acting quickly if you test positive can help you protect yourself from developing severe illness with COVID-19. If you’re unsure where to start, talk to a healthcare provider.

This article is just the beginning. Dive deeper into how this condition is treated and what might be right for you.

Visit the treatment overview

Frequently asked questions

Where can I get vaccinated for COVID-19?
You can check eligibility and find and schedule adult respiratory vaccinations by visiting VaxAssist by Pfizer. You can also talk to a healthcare provider—they can help you find a nearby vaccination site and answer any questions you may have about COVID-19 vaccines.
What if I don’t have a healthcare provider?
You still have options. Community health clinics, urgent care centers, and telehealth services can help you access treatment and support. If you need help getting started, PfizerForAll can help connect you with telehealth providers who can guide you through your care options.
Can severe COVID-19 lead to long COVID?
Long COVID occurs more often in people who had severe COVID-19 illness, but anyone who gets COVID-19 can experience it.

Test your knowledge

If you are at high risk and test positive for COVID-19, you should:

Talk to your doctor

Wait to see if symptoms go away

Correct

Talk to your doctor

Not quite

Correct answer: Talk to your doctor

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References

Ajufo E, Rao S, Navar AM, Pandey A, Ayers CR, Khera A. U.S. population at increased risk of severe illness from COVID-19. Am J Prev Cardiol. 2021; 6:100156. doi: 10.1016/j.ajpc.2021.100156
ACEP COVID-19 Field Guide.  American College of Emergency Physicians. Accessed August 1, 2025. https://www.acep.org/corona/covid-19-field-guide/home-safety/self-isolation.
COVID-19 Vaccine Basics. The Centers for Disease Control and Prevention. September 3, 2024. Accessed July 8, 2025. https://www.cdc.gov/covid/vaccines/how-they-work.html
COVID-19 Vaccination for Women Who Are Pregnant or Breastfeeding. The Centers for Disease Control and Prevention. September 10, 2024. Accessed August 11, 2025. https://www.cdc.gov/covid/vaccines/pregnant-or-breastfeeding.html.
Gregory, CO and Hall AJ. CDC Yellow Book: Health Information for International Travel. The Centers for Disease Control and Prevention. April 23, 2025. Accessed August 1, 2025. https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases/covid-19.html.
Long COVID Basics. The Centers for Disease Control and Prevention. July 24, 2025. Accessed August 1, 2025. https://www.cdc.gov/long-covid/about/index.html.
People with Certain Medical Conditions and COVID-19 Risk Factors. The Centers for Disease Control and Prevention. June 11, 2025. Accessed August 1, 2025. https://www.cdc.gov/covid/risk-factors/index.html.