Atrial Fibrillation

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/9/2026Status: primary verified

What is atrial fibrillation (AFib)? Atrial fibrillation, also known as AFib or AF, is one of the most common types of arrhythmias . Arrhythmias are problems with the rate or rhythm of your heartbeat. They can cause your heart to beat too slowly, too fast, or in an irregular way. If you have AFib, your heart beats irregularly and sometimes much faster than normal. Also, your heart's upper and lower chambers do not work together as they should. When this happens, the lower chambers do not fill completely or pump enough blood to your lungs and body. This can cause symptoms such as dizziness , fatigue , and a pounding heartbeat. AFib may happen in brief episodes, or it may be a permanent condition. It's very important to treat it, since AFib can put you at risk for stroke and other heart conditions . What causes atrial fibrillation (AFib)? AFib is most often caused by changes to the heart's tissue or the electrical signaling that helps the heartbeat. These changes can happen due to different conditions and factors, such as high blood pressure , coronary artery disease , congenital heart defects , infections, and aging. Sometimes the cause is unknown. Who is more likely to develop atrial fibrillation (AFib)? Anyone can develop AFib, but there are certain things that raise your risk for it: Aging. The risk of atrial fibrillation increases as you get older, especially when you are over age 65. Family history and genetics. AFib can run in families. So can heart disease, which raises your risk of AFib. Some lifestyle choices. Your risk is higher if you drink a lot of alcohol, use certain illegal drugs such as cocaine and methamphetamines, or smoke. Having certain health conditions, such as: High blood pressure Diabetes Heart failure Heart valve diseases Obesity Hyperthyroidism Chronic kidney disease COPD and other lung diseases Sleep apnea Race. AFib is more common in people with European ancestry. Recent surgery. You may be at risk of atrial fibrillation in the early days a

Educational only

This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.