Flu (Influenza) Test Test
A flu test checks a sample from your nose or throat to find out if you are infected with the influenza virus. Results are usually positive or negative.
What this test measures
Flu tests check for the most common types of seasonal flu viruses, influenza A and influenza B. They look for either proteins (antigens) or genetic material from the virus in a sample of fluid from your nose or throat.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
A positive result means you most likely have the seasonal flu. It is important to limit contact with others to avoid spreading the virus.
Lower-than-normal results
A negative result means you may not have the flu, but it could be a false negative. Another virus or bacteria may be causing your symptoms.
Frequently asked questions
How is a flu test done?
A health care provider collects a sample of fluid from your nose or throat. Some tests can be done at home using a self-collection kit.
How long does it take to get results?
Rapid tests can provide results in less than 30 minutes. Molecular lab tests may take up to three days.
What does a positive flu test mean?
A positive result means you most likely have the seasonal flu. You should limit contact with others to avoid spreading it.
What does a negative flu test mean?
A negative result means you may not have the flu, but it could be a false negative. Your symptoms might be caused by another virus or bacteria.
Can I test for flu and COVID-19 at the same time?
Yes, combination tests can check for seasonal flu and COVID-19 using one sample. They are available as at-home rapid antigen tests, rapid molecular tests, and lab tests.
Related lab tests
Sources
- MedlinePlus: Flu (Influenza) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.