Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Cold, Flu, & Cough Health Center

Select An Article

Flu Test: How to Find the Virus

Font Size

A doctor can usually tell if you have the flu based on your symptoms, especially if it’s during peak season. But he may want to give you a quick test to be sure the influenza virus is to blame, and not another health problem.

Why Do You Need It?

When your doctor finds the flu virus, he can give you antiviral drugs early on. This is when they work best. If you get diagnosed early --within 48 hours after symptoms show up -- these drugs can ease your symptoms and shorten the illness by a day or so. After the first 2 days, though, these meds won’t do much for you.

A flu test can also help your doctor rule out giving you antibiotics. Those don’t work against viral infections like the flu.

How Does the Test Work?

Your doctor will rub a swab -- just like the cotton swabs in your bathroom, but longer -- along the back of your throat or up your nose. He’ll seal it in a packet and run a quick test on it himself, or send it out to a lab.

How Long Does It Take to Get Results?

If your doctor does the test himself, or they do it in the lab at his office, the answer usually comes back within 15 minutes.

What Does a Test Look For?

It's checking for the virus. Some tests can help your doctor figure out which flu virus you have, influenza A or B.

Are All Tests the Same?

No. The quality of the test depends on the maker, how the test works, and how big a sample of the virus your doctor can collect.

WebMD Medical Reference

Reviewed by Jennifer Robinson, MD on January 20, 2015
Next Article:

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
Natural Cold Flu Remedies Slideshow
cold weather
Allergy And Sinus Symptom Evaluator
Boy holding ear
woman receiving vaccine shot
woman with fever
Waking up from sleep
woman with sore throat