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
WebMD

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
WebMD

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
    WebMD

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community
    WebMD

    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

Heart Health Center

Font Size
A
A
A

What Is Atrial Fibrillation?

Press your hand against your chest. Those little thumps you feel are your heart pumping, moving blood into and out of its chambers and through the rest of your body.

Normally, the top part of your heart (the atria) squeezes first, then the bottom part (the ventricles). The timing of these contractions is what moves the blood. But for more than 2 million Americans, the electrical signals that control this system are off-kilter. Instead of working together, the atria do their own thing. This fast, fluttering heartbeat, what doctors call arrhythmia, is atrial fibrillation, or AFib.

Recommended Related to Heart Health

6 Risky Heart Health Myths

There are a lot of assumptions we make about our hearts. And for each myth, there is often some truth upon which it is founded. Take heart attacks, for instance. Most people imagine they would know when they are having a heart attack. It would be difficult not to recognize symptoms of "the big one" – sweating, soreness in the left arm, and sudden, disabling chest pain. But that’s not always the case. Sometimes the signs are much more subtle or mimic other conditions. "I have heard of instances...

Read the 6 Risky Heart Health Myths article > >

More than annoying, it can be serious. Because your blood isn't moving well, you're at greater risk for heart failure. That's when your heart can't keep up with the needs of your body. Blood can also pool inside your heart and form clots. If one gets stuck in your brain, you can have a stroke.

Who Gets It?

Anyone can have AFib, but it's more common in people who are 60 or older.

Other heart problems can make it more likely:

People with certain medical conditions have a greater chance, too:

Certain medicines (including adenosine, digitalis, and theophylline) can raise the risk of AFib.

Sometimes, it's linked to:

  • Heavy alcohol, caffeine, or drug use
  • Infections
  • The genes you got from your parents

Symptoms

When your heart is in AFib, you might feel:

  • Like your heart is racing or fluttering in your chest (palpitations)
  • Fatigued or weak
  • Dizzy or lightheaded
  • Chest pain or pressure
  • Short of breath

If you have these symptoms, call your doctor and make an appointment as soon as possible. If they last more than 24 hours, go to the hospital.

Sometimes it doesn't cause any symptoms, though. If you're at risk, talk to your doctor about your chances for having AFib, and get regular checkups.

1 | 2 | 3

Today on WebMD

hdl letters stacked up
How to boost your ‘good’ cholesterol.
headache
Learn the causes.
 
Compressed heart
5 habits to change.
heart rate
What’s normal? What’s not?
 
Lower Cholesterol 02
QUIZ
Heart Foods Slideshow
Slideshow
 
Compressed heart
Article
doctor looking at xrays
Video
 
Heart Disease And Ed
SLIDESHOW
Lowering Cholesterol Slideshow
SLIDESHOW
 
lowering blood pressure
SLIDESHOW
Wide Awake For Heart Surgery
VIDEO