Flu Tests: What It Is and What to Expect
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor provides Flu Tests?
A primary care doctor, the doctor you see for everyday health care, can order a flu test. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Most flu tests check a sample of fluid from your nose or throat to find out if you're infected with a flu virus. Rapid antigen tests check your sample for certain proteins, called antigens, found on flu viruses. They are the most common flu tests, but they are not as accurate as other types of flu tests. Molecular flu tests are more accurate than rapid antigen tests, and they check your sample for genetic material from flu viruses.
Why a doctor might recommend it
A flu test can help find out if a flu virus is causing your illness. The results can help your provider decide if medicine could help treat your illness and which one might help you. In some cases, a provider may prescribe medicine to help fight the flu virus, called flu antivirals. They may make your symptoms milder and shorten the time you are sick by about one day. They work best when you start them within 2 days after feeling sick, so early testing may be important, especially if you have a high risk of getting seriously ill from the flu.
How to prepare
- You do not need any special preparation for a swab of your nose or throat, or for a nasal wash.
- If you have flu symptoms and have been near animals that could have had bird flu, tell your provider right away and stay away from others.
What happens during it
For a swab test, a health care professional puts a long swab into your nostril until it reaches the upper part of your throat. They turn the swab for 10 to 15 seconds, take it out, and test the sample.
Recovery
Molecular lab tests are the most accurate type of flu test, but you may wait up to three days because your sample is sent to a special lab. A positive result means you most likely have the seasonal flu, so it is important to limit your contact with others. You can go back to your usual activities when your symptoms have been getting better for at least 24 hours and you have had no fever for at least 24 hours without fever-reducing medicine. A negative result means you may not have the flu, but the flu cannot be ruled out.
Risks and side effects
If your throat or nose is swabbed, you may feel a gagging sensation or a tickle. A test can say you do not have the flu when you really do, which is called a false negative. Because rapid antigen tests can miss the flu, providers may confirm a negative result with a molecular test, especially when flu is spreading widely in the community.
Who performs it
Some tests are done in a health care setting, such as your provider's office, pharmacies, or outpatient clinics. You can also buy at-home tests.
Common questions
Do I need a flu test if I have flu symptoms?
Not always. If the flu is widespread in your area, your provider may be able to diagnose you without a test. Your provider may be more likely to order a test if you have symptoms and a high risk of developing a serious illness from the flu.
How long do flu test results take?
It depends on the test. Rapid antigen tests and rapid molecular tests can give results in less than 30 minutes. Molecular lab tests may take up to three days, because your sample is sent to a special lab.
Can a flu test be wrong?
Yes, a flu test can say you do not have the flu when you really do, which is called a false negative. Rapid antigen tests are not as accurate as molecular flu tests.
Can one test check for flu and COVID-19?
Yes, some tests can. These combination tests use one fluid sample to check for three or more different viruses. Most often, they check for seasonal flu and COVID-19.
How does a direct primary care or concierge doctor fit in?
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
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Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
