COVID-19 testing: what a negative result means and when to retest
A negative test did not detect the virus at that moment. The meaning depends on the test type, timing, symptoms, exposure and the instructions for the specific test.
A negative result is not always a final answer
A negative COVID-19 test means that the test did not detect the virus in the sample. It does not completely rule out infection, especially early in illness or after a recent exposure. The result should be interpreted together with symptoms, the time since exposure, the test type and the manufacturer instructions.
Different tests answer slightly different questions
NAAT tests, including PCR, detect viral genetic material and are generally more sensitive than antigen tests. Antigen tests can be useful because they are convenient and fast, but a single negative antigen result may miss an infection. Follow the instructions supplied with the test and the current local public-health guidance.
When repeat testing can help
CDC advises people using antigen tests to follow FDA repeat-testing recommendations after a negative result. For a negative antigen test, repeat testing may be recommended 48 hours later; the number of tests depends on whether symptoms are present and the circumstances. A healthcare professional can advise whether a different test is useful when the result will affect treatment or contact with a high-risk person.
Act on symptoms and risk, not a result alone
If you have respiratory symptoms, reduce close contact with others where practical, improve ventilation and use a well-fitting mask if you must be around people. If you are older, immunocompromised or have other factors that increase the risk of severe illness, contact a healthcare professional promptly when you develop compatible symptoms or test positive. Do not delay because a single antigen test was negative.
When to seek urgent care
Seek urgent help for trouble breathing, persistent chest pain or pressure, new confusion, inability to wake or stay awake, or other severe or rapidly worsening symptoms.
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This content is general information, not a diagnosis or individual medical advice. Seek urgent help for severe or rapidly worsening symptoms.