Basic Facts

  • Syncope (fainting) is a sudden temporary loss of consciousness, which results when the blood pressure falls sufficiently to reduce the amount of oxygenated blood reaching the brain.
  • Syncope is characterized by rapid onset, short duration and spontaneous complete recovery. 
  • Since syncope can occur without warning, some people who have syncope also have injuries related to falling or other accidents.
  • Heart disease, including blocked coronary arteries, arrhythmias, and congestive heart failure, can cause syncope.

Treatment for syncope focuses on identifying and treating the underlying cause. 

Syncope often recurs, and it can be harmless or life threatening. Therefore, people who experience an episode of syncope should seek medical attention.

Physicians group syncope into three categories: 

  • Noncardiac syncope,
  • Cardiac syncope, and
  • Syncope whose cause is unknown. 
Most commonly, syncope does not occur because of a heart condition (noncardiac syncope). 

Cardiac syncope results from abnormal heart rhythms or a disorder that reduces the heart's ability to pump enough blood to meet the body's needs. 

Syncope FAQ