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Rapid Influenza Antigen (Nasal or Throat Swab)

Does this test have other names?

Rapid influenza diagnostic test, RIDT

What is this test?




Your healthcare provider can test for the flu in several ways. This test usually gives results quickly. Immunofluorescence is another test and uses a staining technique. Results from these tests are not as accurate as viral cultures. But these tests are faster and easier. They are commonly used for the first screening.


Why do I need this test?

You may need this test if you have symptoms of the flu to find out whether you have influenza A or B virus. Symptoms of the flu include:

  • Fever

  • Headache

  • Muscle aches

  • Weakness or tiredness

  • Chills

  • Runny or stuffy nose

  • Cough

  • Pain around your eyes or blurred vision

  • Vomiting or diarrhea



  • Are in the hospital and have a fever or respiratory illness

What other tests might I have along with this test?

You may also need other tests. These include an immunofluorescence antibody test, viral culture, or reverse transcriptase polymerase chain reaction. Testing for influenza antigens is considered a screening test. Your provider may use more accurate tests if he or she thinks the diagnosis needs to be confirmed.

What do my test results mean?


A negative result means that no signs of the virus were found and that you don't have the flu. But the results of this test should be interpreted with caution because rapid influenza antigen tests may have a significant number of false-negative results. This means that you may have the flu even if your results were negative.


It's possible to get a false-positive result, meaning that you aren't really infected. You may need more tests to confirm this. Your health provider may also treat you even if you have a negative test result.

How is this test done?



Does this test pose any risks?


What might affect my test results?


How do I get ready for this test?


Online Medical Reviewer: Haldeman-Englert, Chad, MD
Date Last Reviewed: 6/1/2018
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