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

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

What Is the Flu?

Font Size

Worried about catching the flu? Want to learn some ways to prevent it? Then read on to learn more about influenza -- what it is, how it's spread, and who's at greatest risk for getting it. Knowledge is power when it comes to preventing flu!

What is the flu?

Influenza, commonly known as the "flu," is an extremely contagious respiratory illness caused by influenza A or B viruses. Flu appears most frequently in winter and early spring. The flu virus attacks the body by spreading through the upper and/or lower respiratory tract.

What's the difference between a cold and flu?

The common cold and flu are both contagious viral infections of the respiratory tract. Although the symptoms can be similar, flu is much worse. A cold may drag you down a bit, but the flu can make you shudder at the very thought of getting out of bed.

Congestion, sore throat, and sneezing are common with colds. Both cold and flu bring coughing, headache, and chest discomfort. With the flu, though, you are likely to run a high fever for several days and have body aches, fatigue, and weakness. Symptoms of the flu also tend to come on abruptly. Usually, complications from colds are relatively minor, but a severe case of flu can lead to a life-threatening illness such as pneumonia.

More than 100 types of cold viruses are known, and new strains of flu evolve every few years. Since both diseases are viral, antibiotics cannot conquer cold or flu. Remember: Antibiotics only treat bacterial infections.

Two antiviral medications are available to treat flu. But there are no medications that specifically defeat the common cold. Antibiotics may be helpful only if there is a secondary bacterial infection.

For in-depth information, see WebMD's Flu Treatment.

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