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Covid-19 (Coronavirus Disease 2019)

Medically reviewed by Last updated on Jul 4, 2022.


What you need to know about COVID-19:

COVID-19 is the disease caused by a coronavirus first discovered in December 2019. Coronaviruses generally cause upper respiratory (nose, throat, and lung) infections, such as a cold. The 2019 virus spreads quickly and easily. It can be spread starting 2 to 3 days before symptoms even begin.

What you need to know about variants:

The virus has changed into several new forms (called variants) since it was discovered. The variants may be more contagious (easily spread) than the original form. Some may also cause more severe illness than others.

Signs and symptoms of COVID-19

may not develop. Signs and symptoms usually start about 5 days after infection but can take 2 to 14 days. You may feel like you have the flu or a bad cold. Some signs and symptoms go away in a few days. Others can last weeks, months, or possibly years. You may have any of the following:

  • A cough
  • Shortness of breath or trouble breathing that may become severe
  • A fever
  • Chills that might include shaking
  • Muscle pain, body aches, or a headache
  • A sore throat
  • Sudden changes or loss of your taste or smell
  • Feeling mentally and physically tired (fatigue)
  • Congestion (stuffy head and nose), or a runny nose
  • Diarrhea, nausea, or vomiting

Call your local emergency number (911 in the US) if:

  • You have trouble breathing or shortness of breath at rest.
  • You have chest pain or pressure that lasts longer than 5 minutes.
  • You become confused or hard to wake.
  • Your lips or face are blue.

Seek care immediately if:

  • You have a fever of 104°F (40°C) or higher.

Call your doctor if:

  • You have symptoms of COVID-19.
  • You have questions or concerns about your condition or care.

How COVID-19 is diagnosed:

Your healthcare provider will examine you and ask about your symptoms. Tell him or her if you have any health conditions or are taking any medicines. Any of the following tests may be used:

  • A viral test shows if you have a current infection. Some tests are available for you to do at home. Most use a nasal swab and give the result within 15 minutes. These tests are available at many pharmacy stores. Talk to your provider or pharmacist if you have any questions about this type of test. Testing sites are also available. A sample is taken from your nose or throat with a swab. You may need to quarantine until you get the results from a testing site.
  • An antigen test shows if you have a protein from the COVID-19 virus. This test is often called a rapid test because the results can be available in 30 minutes or less.
  • An antibody test shows if you had a recent or past infection. Blood samples are used for this test. Antibodies are made by your immune system to fight the virus that causes COVID-19. Antibodies form 1 to 3 weeks after you are infected. This test is not used to show if you are immune to the virus.
  • A CT, MRI, ultrasound, or x-ray may be used to check for complications of COVID-19. These may include pneumonia, blood clots, or other complications.


  • Mild symptoms may get better on their own. Some treatments have emergency use authorization (EUA). Examples include monoclonal antibodies and convalescent plasma. These may be given to help prevent worsening of your symptoms. You may also need any of the following:
    • Decongestants help reduce nasal congestion and help you breathe more easily. If you take decongestant pills, they may make you feel restless or cause problems with your sleep. Do not use decongestant sprays for more than a few days.
    • Cough suppressants help reduce coughing. Ask your healthcare provider which type of cough medicine is best for you.
    • To soothe a sore throat, gargle with warm salt water, or use throat lozenges or a throat spray. Drink more liquids to thin and loosen mucus and to prevent dehydration.
    • NSAIDs or acetaminophen can help lower a fever and relieve body aches or a headache. Follow directions. If not taken correctly, NSAIDs can cause kidney damage and acetaminophen can cause liver damage.
  • Severe or life-threatening symptoms are treated in the hospital. You may need any of the following:
    • Medicines may be given to fight the virus or treat inflammation.
    • Blood thinners help prevent or treat blood clots. If you have a deep vein thrombosis (DVT) or pulmonary embolism (PE), you may need to use blood thinners for at least 3 months.
    • Extra oxygen may be given if you have respiratory failure. This means your lungs cannot get enough oxygen into your blood and out to your organs.
    • A ventilator may be used to help you breathe.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

What you need to know about health problems the virus may cause:

You may develop long-term health problems caused by the virus. Your risk is higher if you are 65 or older. A weak immune system, obesity, diabetes, chronic kidney disease, or a heart or lung condition can also increase your risk. Your risk is also higher if you are a current or former cigarette smoker. COVID-19 can lead to any of the following:

  • Multisymptom inflammatory syndrome in adults (MIS-A) or in children (MIS-C), causing inflammation in the heart, digestive system, skin, or brain
  • Shortness of breath, serious lower respiratory conditions, such as pneumonia or acute respiratory distress syndrome (ARDS)
  • Blood clots or blood vessel damage
  • Organ damage from a lack of oxygen or from blood clots
  • Sleep problems
  • Problems thinking clearly, remembering information, or concentrating
  • Mood changes, depression, or anxiety
  • Long-term problems tasting or smelling
  • Loss of appetite and weight loss
  • Nerve pain
  • Fatigue (feeling mentally and physically tired)

What you need to know about COVID-19 vaccines:

Healthcare providers recommend a COVID-19 vaccine, even if you have already had COVID-19. You are considered fully vaccinated against COVID-19 two weeks after the final dose of any COVID-19 vaccine. Let your healthcare provider know when you have received the final dose of the vaccine. Make a copy of your vaccination card. Keep the original with you in case you need to show it. Keep the copy in a safe place.

  • Get a COVID-19 vaccine as directed. The vaccines help prevent severe COVID-19 illness. Vaccination is recommended for everyone 5 years or older. COVID-19 vaccines are given as a shot, usually in 1 or 2 doses. This depends on the age of the person receiving it. A booster dose is recommended for everyone 5 years or older. A second booster is recommended for all adults 50 or older and for immunocompromised adolescents. The second booster is also recommended for anyone who got the 1-dose brand of vaccine for the first dose and a booster. Your provider can give you more information on boosters. He or she can help you schedule all needed doses.
    COVID-19 Immunization Schedule
  • Continue social distancing and other measures. You can become infected even after you get the vaccine. You may also be able to pass the virus to others without knowing you are infected.
  • After you get the vaccine, check local, national, and international travel rules. You may need to be tested before you travel. Some countries require proof of a negative test before you travel. You may also need to quarantine after you return.
  • Medicine may be given to prevent infection. The medicine can be given if you are at high risk for infection and cannot get the vaccine. It can also be given if your immune system does not respond well to the vaccine.

How the 2019 coronavirus spreads:

  • Droplets are the main way all coronaviruses spread. The virus travels in droplets that form when a person talks, sings, coughs, or sneezes. The droplets can also float in the air for minutes or hours. Infection happens when you breathe in the droplets or get them in your eyes or nose. Close personal contact with an infected person increases your risk for infection. This means being within 6 feet (2 meters) of the person for at least 15 minutes over 24 hours.
  • Person-to-person contact can spread the virus. For example, a person with the virus on his or her hands can spread it by shaking hands with someone.
  • The virus can stay on objects and surfaces for up to 3 days. You may become infected by touching the object or surface and then touching your eyes or mouth.

Help lower the risk for COVID-19:

  • Wash your hands often throughout the day. Use soap and water. Rub your soapy hands together, lacing your fingers, for at least 20 seconds. Rinse with warm, running water. Dry your hands with a clean towel or paper towel. Use hand sanitizer that contains alcohol if soap and water are not available. Teach children how to wash their hands and use hand sanitizer.
  • Cover sneezes and coughs. Turn your face away and cover your mouth and nose with a tissue. Throw the tissue away. Use the bend of your arm if a tissue is not available. Then wash your hands well with soap and water or use hand sanitizer. Teach children how to cover a cough or sneeze.
  • Wear a face covering (mask) when needed. Use a cloth covering with at least 2 layers. You can also create layers by putting a cloth covering over a disposable non-medical mask. Cover your mouth and your nose.
    How to Wear a Face Covering (Mask)
  • Follow worldwide, national, and local social distancing guidelines. Keep at least 6 feet (2 meters) between you and others.
  • Try not to touch your face. If you get the virus on your hands, you can transfer it to your eyes, nose, or mouth and become infected. You can also transfer it to objects, surfaces, or people.
  • Clean and disinfect high-touch surfaces and objects often. Use disinfecting wipes, or make a solution of 4 teaspoons of bleach in 1 quart (4 cups) of water.
  • Ask about other vaccines you may need. Get the influenza (flu) vaccine as soon as recommended each year, usually starting in September or October. Get the pneumonia vaccine if recommended. Your healthcare provider can tell you if you should also get other vaccines, and when to get them.
Prevent COVID-19 Infection

Follow social distancing guidelines:

National and local social distancing rules vary. Rules and restrictions may change over time as restrictions are lifted. The following are general guidelines:

  • Stay home if you are sick or think you may have COVID-19. It is important to stay home if you are waiting for a testing appointment or for test results.
  • Avoid close physical contact with anyone who does not live in your home. Do not shake hands with, hug, or kiss a person as a greeting. If you must use public transportation (such as a bus or subway), try to sit or stand away from others. Wear your face covering.
  • Avoid in-person gatherings and crowds. Attend virtually if possible.

Follow up with your doctor as directed:

Write down your questions so you remember to ask them during your visits.

For more information:

  • Centers for Disease Control and Prevention
    1600 Clifton Road
    Atlanta , GA 30333
    Phone: 1- 800 - 232-4636
    Web Address:

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Learn more about Covid-19

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Further information

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