Palpitations may or may not be related to heart-related conditions such as:

• Arrhythmia. An abnormal heartbeat resulting from any change, deviation or malfunction in the heart's normal and natural electrical impulse system. The condition can lead to a skipped, early, rapid or slow beat. This may include atrial fibrillation or any number of tachycardias (abnormally rapid heartbeats), premature atrial contractions and premature ventricular contractions.
  
  
• Mitral valve prolapse. An abnormality of the mitral valve (the heart valve between the left ventricular chamber and the left atrial chamber) in which the valve doesn't close properly.
  
  
• Hyperthyroidism (an overactive thyroid gland).
  
  
• Anemia (a reduced red blood cell count).
  
  
• Coronary artery disease (a chronic disease that involves a “hardening” or atherosclerosis of the coronary arteries).

Palpitations can also be triggered by any of the following:

• Depression
  
  
• Stress
  
  
• Anxiety
  
  
• Panic attacks
  
  
• Stimulants such as caffeine or nicotine, cocaine or amphetamines
  
  
• Alcohol
  
  
• Cigarette smoking
  
  
• Certain over-the-counter and prescription medications, including some for high blood pressure (hypertension), colds (e.g., decongestants), weight loss and thyroid hormone replacement
  
  
• Heavy activity or strenuous exercise
  
  
• High consumption of nutmeg

Other palpitations are random events with no known cause, disappearing as quickly as they began.