Vasovagal syncope is one of the most common causes of fainting. Fainting, also called syncope, is known as a brief loss of consciousness or blacking out. It occurs when there is a temporary restriction of blood flow to the brain, causing a sudden drop in heart rate and blood pressure levels. This disruption of blood flow leading to fainting can be caused by several factors, including the sight of blood, seizures, low blood sugar, extreme emotional distress, or standing for a prolonged period of time.

Vasovagal syncope generally requires no treatment since it is a harmless temporary malfunction in the autonomic nervous system. A doctor may recommend a few medical examinations to exclude most serious causes of fainting such as heart disorders and provide a proper diagnosis for further treatment if necessary.



Before fainting, an individual may experience the following:

  • Lightheadedness
  • Unsteadiness
  • Nausea
  • Cold sweats
  • Yawning
  • Skin paleness
  • Blurred or tunnel vision

Recovery from a vasovagal episode tends to occur within less than a minute of fainting. Standing up too soon may cause an increased risk of fainting again. 



Vasovagal syncope occurs when a particular trigger causes the part of the nervous system that regulates the heart rate and blood pressure levels, to temporarily malfunction. The drop in blood pressure and slowed heart rate restricts blood supply to the brain, in turn causing an individual to faint.  A simple episode known as a vasovagal attack or neutrally-mediated syncope is the most common type of fainting spell.


Common triggers for vasovagal syncope include the following:

  • Standing for a prolonged period of time
  • Standing up too quickly
  • Exposure to high temperatures
  • The sight of blood
  • Having blood drawn
  • Fear of bodily injury
  • Stressful incident
  • Straining during a bowel movement
  • Dehydration
  • Lack of sleep
  • Hunger
  • Severe menstrual cramps
  • Uncontrolled diabetes
  • Certain medications
  • Certain medical conditions affecting the nervous system



In most cases of vasovagal syncope, treatment is not necessary. In more severe cases when fainting spells are frequent, the main goal is to find the underlying cause. A doctor may recommend one of the following treatment options:

  • Midodrine: A type of medication used to treat low blood pressure levels
  • Doing specific foot exercises to decrease the accumulation of blood in the legs
  • Wearing graded compression stockings to improve blood circulation
  • Learning to tense the muscles in the legs, arms and torso through specific exercises
  • Adding more salt to daily meals
  • Increasing potassium intake
  • Drinking plenty of fluids to stay hydrated
  • Avoiding prolonged standing
  • Biofeedback training: A technique used to control a fast heart beat by sending warning signals through electrical sensors during unusual heart activity
  • Surgery, if necessary (insertion of a electrical pacemaker to help regulate the heart beat)




A sure prevention of vasovagal syncope episodes is unlikely even with treatment. Particular measures that can help an individual during an episode include lying down and lifting the legs to allow gravity to direct blood flow back to the brain.