Atrial Fibrillation: Causes, Risks, and Triggers

Atrial fibrillation (AFib) is the most common problem with the heartbeat's rate or rhythm. Disorganized signals make the heart's two upper chambers (the atria) squeeze very fast and out of sync. They contract so quickly that the heart walls quiver, or fibrillate.

It can happen because the heart's electrical system has been damaged, typically from other conditions that affect the heart. But in at least 1 of every 10 AFib cases, other things may be at play. Sometimes, doctors can't figure out what's causing AFib.

Even after you've been diagnosed with the condition, you may be able to control your AFib and avoid having an episode if you know what triggers them for you.

Age and Family

Your risk increases, especially after age 60. As people grow older, they're more likely to develop heart disease and other conditions that can cause AFib.

If someone in your close family had or has it, there's a greater risk for you, too.

Heart Disease

Since AFib is a problem with your heart, it's not surprising that other heart issues raise the risk of AFib, including:

Sick sinus syndrome can also make it more likely. With this condition, the heart's electrical signals misfire, and the heart rate alternates between fast and slow.

AFib can happen during a heart attack.

It's the most common complication after heart surgery. It will happen to 2 or 3 out of every 10 people recovering.

Other Health Conditions

Medical problems not related to your heart can also increase the likelihood that you'll have AFib:

Newer research suggests that people who take high doses of steroids, perhaps for asthma or other conditions that cause inflammation, may be at greater risk for AFib. If your chances are higher anyway, this treatment can trigger an episode.

Habits and Lifestyle

A large amount of alcohol, particularly binge drinking, can trigger AFib. But drinking only a modest amount is enough for some people.

Caffeine, cigarettes, and other stimulant drugs can set off AFib. Caffeine will probably affect you more if you don't usually drink it.

When you're under a lot of stress or feeling worn out, that could trigger an episode or make your symptoms worse.

WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on November 21, 2015



Merck Manual: "Atrial Fibrillation and Atrial Flutter."

Cleveland Clinic: "What is Atrial Fibrillation?"

National Heart, Lung and Blood Institute: "Who is at Risk for Atrial Fibrillation?" "What Causes Atrial Fibrillation?" and "What is Atrial Fibrillation?"

American Heart Association/American Stroke Association: "When the Beat is Off: Atrial Fibrillation." "Diabetes associated with risk of atrial fibrillation."

The Lancet: "Predicting atrial fibrillation - Authors' reply."

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