Diagnosing COVID-19
There are two kinds of tests available to diagnose COVID-19: tests for current infection (viral tests) and tests for past infection (antibody tests). Learn more about these types of tests, when you should get tested for COVID-19 and what to do after your test results.
Viral Tests
Viral tests for a current COVID-19 infection. They use respiratory samples, such as a swab from inside your nose or saliva from your mouth, to determine if you are currently infected with SARS-CoV-2, the virus that causes COVID-19. Depending on the testing site, results may be available within a few minutes, a few hours or may take several days if the sample is sent to a laboratory for analysis.
If you think you have been exposed to the virus and are exhibiting symptoms, get tested. Take the CDC’s COVID-19 Viral Testing Tool or read below.
You should get tested for COVID-19 if you:
- Are experiencing symptoms of COVID-19
- Had a known exposure to someone with suspected or confirmed COVID-19.
- At least 5 days after exposure with day 0 being the day of contact. While you are waiting on test results, quarantine from others to limit the possibility of disease spread.
- Are not up to date on your COVID-19 vaccines and are prioritized for community screening of COVID-19.
- Have been asked or referred to get tested by your school, workplace, healthcare provider, or state, local, tribal or territorial health department.
You do not need to be tested if you:
- Tested positive for COVID-19 in the past three months and recovered. If you develop new symptoms, you should be tested.
Results from your viral test will indicate that you either:
- Test positive for the virus that causes COVID-19. Learn more about next steps to take and ways to help prevent the spread of disease to others.
- Test negative for COVID-19.This means you were not infected at the time the sample was collected and analyzed. This doesn’t mean that you won’t get sick, only that you didn’t have COVID-19 when you were tested. You can think of this like a single snapshot in time that doesn’t determine if you had COVID-19 previously or if you will be exposed and infected in the future.
- If you have symptoms of COVID-19, you might have received a false negative result and still have COVID-19 so you should still isolate from others. Contact your healthcare provider about your symptoms, especially if they get worse, about further testing and how long to isolate.
- If you do not have symptoms of COVID-19, you are likely not infected but you could still get sick.
- If you are fully vaccinated there is no need to self-quarantine at home.
- If you are not fully vaccinated, you should quarantine at home for a set amount of time depending on your situation. Contact your healthcare provider who will want to stay updated on your progress.
- If you later experience symptoms, or have close contact with an infected individual, you should speak with your doctor to determine if you need another test.
Antibody Tests to Detect Past Infection
Antibody tests are performed by drawing blood and conducting a laboratory test to check for antibodies that would only be present if you had a past infection of SARS-CoV-2, the virus that causes COVID-19. An antibody test should not be used to determine current infection as it can take your body one to three weeks after infection to make antibodies. If you think you were previously infected with COVID-19, you should speak with your doctor about your symptoms or exposure to infected individuals.
Antibody testing is not recommended to determine immunity or whether you need to get vaccinated.
Results from your antibody test will be positive if you were previously infected with COVID-19 and negative if you have not been previously infected. Regardless of the status of your test, you should take steps, including getting vaccinated, to protect against COVID-19.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.
Page last updated: May 10, 2022
