Syncope

This is the medical term for "passing out" or "fainting." During syncope, a temporary loss of consciousness together with loss of muscle tone (slumping over or falling) occurs, however the patient recovers quickly and spontaneously. Syncope is due to a transient decrease in blood flow to the brain.

There are many conditions that can cause syncope—some of which may be related to heart disease such as certain heart valve disorders or arrhythmias. The most common condition—the "common faint"—is due to a transient blood pressure and/or heart rate decrease and is typically seen in healthy individuals (for example during blood draws or painful events).

All patients with syncope should be thoroughly evaluated especially if they have known heart disease, as some causes for syncope can potentially be dangerous.