COVID-19 (Coronavirus disease 2019) is an infection of the airways and lungs. It causes a minor cold-like illness in most. Others may develop severe breathing problems or illness.


COVID-19 is caused by a new type of coronavirus that was first seen in humans in 2019. This new form has led to an outbreak of COVID-19 in many countries.

The virus is passed from person to person. Someone who is ill can release droplets with the virus when they sneeze or cough. The droplets can enter the mouth, nose, or eyes of those near the infected person. This seems to be the most common method of passing the illness. The droplets can also land on surfaces around someone who is ill. The virus may then pass when someone else touches the surface, and then touches their mouth, nose, or eyes.

Risk Factors

Risk of COVID-19 may be higher in people who:

  • Have close contact with someone who has COVID-19. Close contact often means sharing a home or caring for someone with the disease.
  • Live in or visit areas with active outbreaks.
  • Have close contact with someone who has traveled to high-risk areas.

Active outbreaks of COVID-19 have been reported in many countries. Follow trusted sources like government sites and Center for Disease Control (CDC) to see the risk in your area.

The risk of severe infections may be more common in:

  • Older adults
  • People with health issues such as high blood pressure, heart disease, or diabetes


Symptoms can range from mild to severe. They often appear 2 to 14 days after contact with the virus. Common symptoms may include:

  • Fever or chills
  • Cough
  • Shortness of breath
  • Fatigue
  • Pain in muscles
  • Headache
  • Loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

Call your doctor if you think you have been exposed to coronavirus and now have fever, cough, or problems breathing . Call before you go to the doctor’s office. This will help them send you to the right place and lower the risk of infecting other patients.

Some may have more severe symptoms. Get medical care immediately for:

  • Trouble breathing
  • Nonstop chest pain or pressure
  • Changes in awareness, confusion, or problems waking
  • Bluish color in lips or face


The doctor will ask about symptoms. There are many viruses and health issues that cause similar symptoms. The doctor may ask about risk factors to narrow possible causes. They may suspect COVID-19 if you are in high-risk areas or have had close contact with someone who has or may have COVID-19.

Testing may not be needed if symptoms are mild. The doctor will explain why tests may or may not be done. If tests are done, a sample of fluid from the nose or throat, or a blood sample will be sent to a lab. This can confirm COVID-19.


There is no treatment for COVID-19 itself. The body will need time to clear it out.

Mild symptoms can be handled at home. Basic care, such as rest and fluids, will help. Hospital care may be needed for severe symptoms. Oxygen therapy and medicine may be needed to help breathing. Intubation may be needed for those that have very sick lungs. The hospital care team will also be able to respond to related problems.

Other steps can help to stop the spread of infection to others:

  • Stay at home while you are ill. Avoid public areas, work, school, or public buses, trains, or cars. Only leave home if you need medical care until you have fully recovered. Ask your doctor how long you should follow these steps. You can stop isolation if all of the following are true:
    • It has been at least 10 days since your first symptoms (people who are severly ill or have weak immune system may need longer)
    • You are fever-free for 24 hours without fever reducing medicine
    • Other symptoms are getting better.
    If you had a positive test but no symptoms, isolate for at least 10 days. You may need longer isolation if you were very sick, in the hospital, or have a weak immune system.
  • Try to avoid close contact with others at home. Stay about 6 feet away from others. If possible, spend most of your time in a separate room.
  • Wipe down common surfaces in the home. This includes doorknobs, counters, or sinks. Use household cleaners and wipe down these surfaces each day.
  • Wash your hands often. Ask everyone else in your house wash their hands often, too. Wash with soap and water for at least 20 seconds. Use alcohol-based hand cleaner if soap and water is not on hand.
  • Cough or sneeze into a tissue. Throw away the tissue after use. Cough or sneeze into your elbow if you do not have a tissue.
  • Use a face mask if you will be close to others such as sharing a room or vehicle. You should also wear a mask if you are going to a doctor’s office or need to be in other public places.
  • Avoid close contact with pets while you are sick. There is no proof of the virus passing to pets. This is a safety step until more is known about this virus.

Follow these steps until your doctor has said it is OK to stop.


To help lower your chance of COVID-19:

  • Get a COVID-19 vaccine.
  • Wash your hands often. Wash with soap and water for 20 seconds each time. Use alcohol-based hand cleaner if soap and water is not available.
  • Try to stop touching your eyes, nose, or mouth.
  • Follow recommendations in your community which may include:
    • Keep a safe distance (about 6 feet) from other people.
    • Wear a facemask when in large group and public space where safe distance is difficult. The mask should be snug to the face and cover nose and mouth.
    • Avoid large gatherings.
  • Avoid travel to high risk areas. Check with government travel restrictions and precautions.

Stay aware of community news. Follow any recommended steps. This may include periods of time when you are asked to stay at home and avoid large groups. This can help to protect you and your family. It can also help to slow the spread of illness in the community.


Centers for Disease Control and Prevention

World Health Organization


Health Canada

Public Health Agency of Canada


Coronavirus disease (COVID-19) advice for the public. World Health Organization website. Available at: Accessed April 14, 2021.

Coronavirus Disease 2019 Information for Travel. Centers for Disease Control and Prevention (CDC) website. Available at: Accessed April 14, 2021.

COVID-19 (Novel Coronavirus). EBSCO DynaMed website. Available at: Accessed April 14, 2021.

COVID-19. United States Department of Labor website. Available at: Accessed April 14, 2021.

Q&A on coronaviruses (COVID-19). World Health Organization website. Available at: Accessed April 14, 2021.

What to Do If You Are Sick With Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention (CDC) website. Available at: Accessed April 14, 2021.

What you need to know about coronavirus disease 2019 (COVID-19) factsheet. Centers for Disease Control and Prevention (CDC) website. Available at: Accessed April 14, 2021.

World Health Organization (WHO) technical documents for coronavirus disease (COVID-19). World Health Organization website. Available at: Accessed April 14, 2021.

Last reviewed April 2021 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD  Last Updated: 09/23/2020