Atrial fibrillation (also known as AF or AFib) is the most common type of arrhythmia (irregular heartbeat or heart rhythm). Symptoms of AF can vary. You may experience symptoms or you may not. You may not even know you have AF; some people don't realize they do until they get a routine test done with their doctor (read "Diagnosing atrial fibrillation" for more on diagnosing AF). The same person can sometimes feel AF symptoms and at other times not feel it at all.

Atrial fibrillation can occur once in a while, or it may be present continuously.

Symptoms of AF include:

  • palpitations - the most common symptom, typically experienced as a rapid thumping in the chest
  • irregular and rapid heartbeat
  • chest pain, discomfort, or tightness
  • dizziness, lightheadedness, or fainting
  • fatigue
  • shortness of breath or difficulty breathing, especially with exertion or anxiety
  • sweating
  • nausea
  • becoming easily tired after exercising or being active
  • weakness

How often and the length of time these symptoms occur can vary, as well as how severe the symptoms are. Some people do not feel any symptoms at all and feel fine, while others have debilitating symptoms that severely affect their quality of life.