Overview

Vasovagal syncope (vay-zoh-VAY-gul SING-kuh-pee) occurs when you faint because your body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. It may also be called neurocardiogenic syncope.

The vasovagal syncope trigger causes your heart rate and blood pressure to drop suddenly. That leads to reduced blood flow to your brain, causing you to briefly lose consciousness.

Vasovagal syncope is usually harmless and requires no treatment. But it's possible you may injure yourself during a vasovagal syncope episode. Your doctor may recommend tests to rule out more serious causes of fainting, such as heart disorders.

Feb. 12, 2016
References
  1. Syncope. Merck Manual Professional Version. http://www.merckmanuals.com/professional/cardiovascular_disorders/symptoms_of_cardiovascular_disorders/syncope.html#v1145025. Accessed Dec. 14, 2015.
  2. Stone CK, et al., eds. Immediate management of life-threatening problems causing syncope. In: Current Diagnosis & Treatment: Emergency Medicine. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com. Accessed Dec. 14, 2015.
  3. Jardine DL. Vasovagal syncope: New physiologic insights. Cardiology Clinics. 2013;31:75.
  4. Aminoff MJ, et al. Seizures & syncope. In: Clinical Neurology. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com. Accessed Dec. 14, 2015.
  5. Angaran P, et al. Syncope. Neurology Clinics. 2011;29:903.
  6. Olshansky B. Upright tilt table testing in the evaluation of syncope. http://www.uptodate.com/home. Accessed Dec. 15, 2015.