More than 2 million Americans have AFib. It's more common in people 60 and older.

Other heart problems can make it more likely:

Heart disease due to high blood pressure

Heart valve disease

Heart muscle disease (cardiomyopathy)

Heart defect from birth (congenital heart defect)

Heart failure

Past heart surgery

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

Long-term lung disease (such as COPD)

Overactive thyroid gland

Sleep apnea

Medicines (including adenosine, digitalis, and theophylline) can raise the chance of having AFib.

Sometimes, it's linked to:

Heavy alcohol, caffeine, or drug use

Infections

Genetics