Atrial Fibrillation (AFib): Symptoms & Signs

Medically Reviewed on 9/10/2019

Symptoms of atrial fibrillation occur when the upper chambers of the heart (atria) beat in a disorganized fashion. Atrial fibrillation is a type of arrhythmia. Characteristic symptoms include

In some cases, chest pain can be an associated symptom, particularly if there is also cardiovascular disease present. (Chest pain or pressure warrants urgent medical evaluation.) Other symptoms of atrial fibrillation are

Causes of atrial fibrillation (AFib)

The cause of atrial fibrillation is an abnormal heart rhythm, in which electrical signals come from the wrong location within the heart. These abnormal signals are rapid and irregular and cause atrial fibrillation. The reasons for the abnormalities in signaling are unknown.

Other atrial fibrillation (afib) symptoms and signs

American Heart Association. "Atrial Fibrillation Medications." July 2016. <>.

Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.