What to Know About COVID-19

Medically Reviewed By Joseph Vinetz, MD
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COVID-19 is a disease caused by a type of coronavirus. Most people with COVID-19 experience mild respiratory symptoms, but some cases can be more severe. Cases usually resolve on their own with at-home treatments, similar to a cold or the flu. For those more at risk of severe illness, doctors can prescribe medications to help prevent the disease from progressing. Getting vaccinated against the virus that causes COVID-19 can reduce your chance of becoming severely ill, or dying from the disease.

Keep reading to learn about COVID-19, its symptoms, treatment options, and answers to frequently asked questions.

What is COVID-19?

hand holding positive covid-19 rapid antigen test
Sean Locke/Stocksy United

COVID-19 stands for “coronavirus disease 2019.” It is a respiratory illness that can lead to pneumonia and other serious conditions. In some cases, it can be fatal.

Anyone can get COVID-19. Most cases are mild, but adults over the age of 65 and those with certain underlying medical conditions are more at risk of developing serious illness, says the Centers for Disease Control and Prevention (CDC).

People can also experience a wide range of health problems 4 or more weeks after getting COVID-19, known as post-COVID, or “long” COVID.

What are the symptoms of COVID-19?

COVID-19 symptoms primarily involve the respiratory tract. They can vary in severity from mild cold symptoms to flu-like symptoms to serious respiratory distress. Symptoms can develop anywhere from 2–14 days after exposure to the virus. Some people do not experience any symptoms.

Common symptoms of COVID-19

Learn about unusual signs and symptoms of COVID-19, including “COVID toes.”

Serious symptoms and when to contact your doctor

Seek immediate medical care if you experience any of these serious symptoms:

  • pale, gray, or bluish lips, face, nails, or skin
  • sudden or severe confusion
  • extreme sleepiness, difficulty staying awake, or severe fatigue
  • chest pain or pressure that gets worse with deep breathing or coughing
  • severe shortness of breath or trouble breathing

If you suspect you have COVID-19 and may be at risk of developing severe symptoms, contact a healthcare professional immediately about treatment. Even if you have mild or no symptoms, the CDC says you can reduce your chance of becoming seriously ill or dying by starting treatment within a few days of infection.

Learn more about COVID-19 symptoms you shouldn’t ignore.

What causes COVID-19?

COVID-19 is caused by the virus SARS-CoV-2. It belongs to the coronavirus family, which causes a variety of respiratory diseases, including some head and chest colds. An outbreak of SARS-CoV-2 infections in 2019 started the coronavirus pandemic.

SARS-CoV-2 is related to SARS-CoV, the virus that causes SARS, another respiratory illness. SARS outbreaks occurred in 2002 and 2004, killing about 1 in 10 people that had an infection.

How does COVID-19 spread?

The virus that causes COVID-19 spreads through droplets exhaled by someone who is infected. You can contract the virus by:

  • breathing in air that contains virus particles from someone who is infected
  • having droplets containing the virus land on your eyes, nose, or mouth, such as from a sneeze or cough
  • touching an object with virus particles on it and then touching your eyes, nose, or mouth

What are the risk factors for COVID-19?

Anyone who contracts the virus can develop COVID-19. Most people will not get seriously ill, according to the CDC. However, certain factors can increase the chance of developing severe illness. These include:

  • being over the age of 65
  • having a chronic medical condition, such as diabetes
  • having a weakened immune system
  • being overweight or having obesity
  • being pregnant or having recently been pregnant
  • having certain disabilities

Learn more about medical conditions that increase your risk of severe COVID-19.

How can you prevent COVID-19?

You can reduce your chance of getting COVID-19 by following these tips:

  • Clean and disinfect: Regularly clean high touch surfaces in your home. Use a disinfectant after cleaning if someone is sick or has tested positive for COVID-19.
  • Keep a safe distance: Stay at least 6 feet away from people who are sick. When indoors in public, stay 6 feet from others if you are not fully vaccinated or are at high risk.
  • Wash your hands: Wash your hands often for at least 20 seconds with soap and water, especially if you may have come into contact with the virus.
  • Avoid poorly ventilated spaces: When indoors, try to let in fresh air by opening doors or windows.
  • Wear a mask: Wear a properly fitting mask in indoor public spaces, whether or not you are vaccinated.
  • Get vaccinated: Get vaccinated against COVID-19 and stay up to date. This is the best way to slow the spread of the virus.

Learn about the differences between the COVID-19 vaccines.

Medications to prevent COVID-19

The Food and Drug Administration (FDA) has authorized the use of an investigational drug called tixagevimab plus cilgavimab (Evusheld). Evusheld can help prevent infection with the virus that causes COVID-19. People with compromised immune systems or who are allergic to COVID-19 vaccines may be eligible for Evusheld. Talk with your doctor to see if this option is right for you.

How is COVID-19 diagnosed?

The symptoms of COVID-19 are similar to other respiratory conditions, such as the common cold and flu. The only way to know for certain if you have COVID-19 is to test for the presence of the virus that causes it.

The CDC recommends getting tested if you have symptoms of COVID-19, which may include fever and cough.

Learn more about the different types of COVID-19 tests.

How is COVID-19 treated?

There are several options for COVID-19 treatment, including at-home remedies and prescription medications.

At-home treatment

Most people with COVID-19 experience mild symptoms that can be treated at home. You can take care of yourself by getting rest and staying hydrated. You can also take over-the-counter medications to help you feel better, like you would with a cold.

It is important to keep track of your symptoms. If they do not improve with these remedies or your symptoms worsen, contact a doctor.

If you experience any emergency warning signs such as trouble breathing, call 911.

Prescription medications

Doctors can prescribe antiviral and other medications to treat mild to moderate cases of COVID-19 in people with increased risks. The specific treatment depends on several factors, such as the availability of medications and the strain of the virus that caused the infection.

Medication options may include:

  • remdesivir (Veklury)
  • nirmatrelvir with ritonavi (Paxlovid)
  • molnupiravir
  • bebtelovimab (Lagevrio)

Learn more about COVID-19 treatment options.

What are the potential complications of COVID-19?

COVID-19 can develop into a serious illness and become life threatening. Potential complications from COVID-19 include:

Some people who have had COVID-19 can also experience effects long after their initial infection, known as long COVID. Long COVID occurs more often in people who have had severe cases, but anyone who has had COVID-19 can experience post-COVID symptoms.

Frequently asked questions

Below are some other frequently asked questions about COVID-19.

Is coronavirus the same as SARS?

No. Coronavirus refers to any member of the coronavirus family of viruses, including SARS-CoV-2, which is the virus that causes COVID-19. SARS is a form of pneumonia caused by a different coronavirus, known as SARS-CoV. They are both rare examples of an animal coronavirus mutating enough to transition to human hosts.

Is COVID-19 more dangerous than the flu?

COVID-19 can be more dangerous than the flu for several reasons. It can cause more serious illness than the flu in some people, spread more easily, and lead to long-term symptoms known as long COVID. COVID-19 can also lead to complications like blood clots and multisystem inflammatory syndrome in children and adults.

What kills coronavirus?

Several products can be used to disinfect for coronavirus, including bleach, ethyl alcohol, hydrochlorous acid, and others. The Environmental Protection Agency (EPA) has a detailed list and a tool you can use to search for a specific product.

Do I have immunity if I already had COVID-19?

You have some immunity if you have already had COVID-19. However, you can get an infection again and develop COVID-19 a second time. Whether or not this occurs depends on several factors, including the specific strain of the virus and the time since the first infection.

How long does COVID-19 last?

For most people, COVID-19 is a mild to moderate illness with symptoms improving after about a week. People with more severe cases may take 6 weeks or more to recover.


COVID-19 is an infectious disease that causes mild to severe respiratory symptoms. In some cases, it can become life threatening. The virus that causes COVID-19 spreads easily between people. Mild symptoms include cough, fatigue, fever, body aches, shortness of breath, and loss of taste or smell.

Most people experience mild symptoms and recover at home with rest and fluids, similar to a cold or the flu. Some people develop more moderate or severe symptoms and may need hospital care to prevent or treat complications. Vaccines are available to help you protect yourself against COVID-19.

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Medical Reviewer: Joseph Vinetz, MD
Last Review Date: 2022 Jun 10
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.