Coronavirus (COVID-19)

Last Updated May 2023 | This article was created by editorial staff and reviewed by Robert "Chuck" Rich, Jr., MD, FAAFP

COVID-19 is a disease caused by a coronavirus called SARS-CoV-2. Coronaviruses, which can infect people and some animals, spread through respiratory droplets from coughing, sneezing, and even talking. SARS-CoV-2 is a new coronavirus identified in 2019 that causes COVID-19.

SARS-CoV-2, like other viruses, is able to mutate when it spreads between people. These mutations lead to variants that can behave differently from the original virus strain, like the recent Delta and Omicron variants. These variants can be transmitted between people more easily, produce different symptoms, and cause severe disease.

What are the symptoms of COVID-19?

COVID-19 symptoms range from mild to severe. It takes 2-14 days after exposure for symptoms to develop. Symptoms may include:

  • Fever
  • Cough
  • Shortness of breath
  • Chills
  • Repeated shaking with chills
  • Muscle pain or aches
  • Headache
  • Sore throat
  • New loss of taste or smell
  • Runny nose and/or congestion
  • Nausea and vomiting
  • Diarrhea

You may never develop symptoms after being exposed to COVID-19, which is referred to as being asymptomatic. But you can still spread the virus to others without symptoms.

What causes a COVID-19 infection?

The most common way to get COVID-19 is by inhaling respiratory droplets in the air. When a person with COVID-19 breathes, coughs, or sneezes, tiny droplets leave their mouth and nose and go into the air. You can’t see these droplets. If you’re within 6 feet of that person, you may breathe in those droplets. You won’t know you’ve done it. But you may get the germs that cause COVID-19 in your body.

COVID-19 also can be shared if you touch a surface an infected person has touched. Some examples include door handles, elevator buttons and shopping carts. The germs can get into your body if you then touch your eyes, nose, or mouth.

How is COVID-19 diagnosed?

If you believe you have COVID-19, the first step is to get a test. Testing availability may differ depending on where you live. Check your local health department to see what locations near you are doing testing. This may include hospitals and pharmacies that offer drive-thru testing. This will allow you to stay in your car to prevent the possible spread of COVID-19. Depending on the location, someone may approach your car to collect a sample, or they may ask you to collect it yourself. Samples for COVID-19 viral tests are collected through nasal swabs. Depending on where you get your test, you may get your results the same day or you may have to wait a few days. Find out more about COVID-19 testing.

You can also get at-home tests. Some are still available for free through the U.S. government. Or you can purchase them at your local pharmacy. Some insurance plans will also pay for at-home tests. Learn more about at-home testing.

If you have – or believe you have – COVID-19, you should self-isolate to prevent spreading the infection. It’s also important to remember that even if you get a negative test, you may still need to self-isolate if you’ve been exposed to COVID-19. This is because it can take time after exposure for your sample to show a COVID-19 infection.

Do I need to quarantine if I have been exposed to COVID-19?

The Centers for Disease Control and Prevention (CDC) updated their quarantine and isolation guidance in March 2023.

  • If you have been exposed to COVID-19, are fully vaccinated and do not have symptoms, you do not have to quarantine, but should get tested within 5 days or if symptoms emerge.
  • If you received a positive COVID-19 test, or were exposed to someone with COVID-19 and are not fully vaccinated against COVID-19, you should stay at home and away from other people for 5 days, followed by 5 days of wearing a mask. You should avoid travel and contact with high-risk individuals as a precaution.

Keep in mind that local officials may determine quarantine requirements for different states or counties. Reducing the length of quarantine may not be an option in all areas. If you need to quarantine, you should follow any local requirements and recommendations.

Can COVID-19 be prevented or avoided?

Getting the COVID-19 vaccine can protect you – and others around you – from getting very ill from COVID-19. Wearing well-fitting masks in public settings is very effective at preventing spread of the virus. While any mask will provide protection, people are encouraged to wear higher quality masks (KN95, Kf94, or N95) when possible. Even if you wear a mask, you should still avoid people who are sick or be cautious in large crowds. Stay home if you are sick and talk with your doctor about getting tested. Cover your cough with a tissue, or cough into your upper sleeve or elbow. Do not cough into your hands.

Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom, before eating, and after blowing your nose, coughing, or sneezing. If soap and water are not readily available, use an alcohol-based hand sanitizer with at least 60% alcohol. Avoid touching your mouth, nose, or eyes.

COVID-19 treatment

As with a cold or the flu, drink fluids and get plenty of rest. Symptoms of COVID-19 usually go away on their own. If symptoms feel worse than a common cold, contact your doctor. He or she may prescribe pain or fever medication.  If you are having trouble breathing, seek immediate medical care.

The FDA advises people to be cautious of websites and stores selling products that claim to prevent, treat, or cure COVID-19. Additionally, do not take any form of chloroquine, ivermectin or other medicines unless they have been prescribed for you by your family doctor. There are a few options to treat COVID-19 for people at high risk of serious illness. Your physician will decide which option is appropriate for you.

Is there a vaccine for COVID-19?

Yes, there are three vaccines for COVID-19. Pfizer-BioNTech and Moderna have full FDA approval for all ages. The Johnson & Johnson (Janssen) vaccine has been authorized for emergency use only in people 18 years of age and older in the United States. The AAFP and CDC recommend the Pfizer-BioNTech’s coronavirus vaccine for people 5 and older, and the Moderna and Johnson & Johnson vaccines for people 18 and older. In most situations, the Pfizer and Moderna vaccines (called mRNA vaccines) are preferred. To maximize protection, COVID-19 vaccine booster doses are now recommended for adults aged 12 and older. People 12-17 years old can only receive a booster dose of Pfizer.

Updated boosters for the Omicron variant were made available beginning in September 2022. In March 2023, the FDA authorized the bivalent Pfizer-BioNTech COVID-19 vaccine as a booster dose for children 6 months through 4 years of age.

Living with COVID-19

Post-COVID Syndrome is a term for the wide range of new, returning, or ongoing health problems that occur after a COVID-19 infection. It may also be referred to as Post-COVID condition, long COVID, long-haul COVID and chronic COVID.

Symptoms can come from the long-term effects of the viral infection, a long illness and hospitalization related to severe COVID-19 disease. They include difficulty breathing, fatigue, malaise, “brain fog” or cognitive impairment, cough, chest pain, headache, rash, impaired daily function, etc. View a complete list of symptoms and talk with your family doctor is you’re experiencing any symptoms after a COVID-19 infection.

Questions to ask your doctor

  • What can I do to prevent my friends and family from getting COVID-19?
  • What over-the-counter medicines work best for my symptoms?
  • Am I at risk of complications if I get COVID-19?
  • What symptoms should I seek medical advice for?

Read More from

Know the Facts About COVID-19

Handwashing and COVID-19

Hand Sanitizers and COVID-19

 Top 10 Tips From Your Family Doctor

Other Resources

Centers for Disease Control and Prevention: Coronavirus Disease 2019

Centers for Disease Control and Prevention: COVID-19 Testing Overview