Syncope (Fainting)


Syncope is the medical term for fainting. Syncope results from a drop in blood pressure or heart rate.  Syncope occurs when a reduction in blood flow to the brain causes a temporary loss of consciousness. You should contact your doctor to determine the cause of your fainting and receive treatment.



  • Sudden drop in blood pressure, which may occur from being dehydrated, exhaustion, heavy sweating, blood loss, or from standing up quickly. Pain, emotional stress, or fear can cause fainting. 
  • Certain medications
  • Hyperventilation
  • Alcohol or illegal drug use can cause syncope. 
  • Further, it may occur with urination, a bowel movement, coughing, or after standing or sitting for too long. 
  • Neurally mediated syncope (NMS), Neurocardiogenic, vasovagal, vasodepressor, or reflex mediated syncope.  It is more common in children and young adults, but may occur at any age.  A drop in blood pressure or heart rate causes the fainting.
  • Syncope that occurs with exercise, heart palpitations, or irregular heartbeats may be related to a heart problem.  People with a family history of recurrent syncope or sudden death may have a higher risk of cardiac related syncope.



You may feel weak, dizzy, lightheaded, or nauseated prior to fainting.  You may turn pale and sweat.  You may have a ringing in your ears and sounds may seem like they are fading out.  You may have a visual disturbance, such as everything is “graying out.”  These symptoms may last for a few seconds before a brief loss of consciousness.  Recovery from fainting is rapid, although you may feel nauseous and sweating initially.



Your doctor will start to determine if you simply fainted, had a seizure, or if you have a heart condition.  Your doctor will review your medical history and conduct a physical examination and some tests to determine the cause of your fainting.  Your doctor may examine your heart, lungs, and nervous system. Your blood pressure will be measured while you are in different positions.

Cardiac tests may be performed if you have recurrent syncope or if your doctor suspects a heart problem.  The tests may include a chest X-ray, electrocardiogram (ECG), and echocardiogram.  An exercise stress test involves monitoring your ECG and blood pressure while you exercise on a treadmill.  The exercise stress test provides information about how your heart works with an increased blood flow.  You may wear a Holter monitor for periods of 24 hours or more. 


People with NMS may be treated with medication and may be advised to eat a high-salt diet and drink plenty of fluids.  They should sit or lie down when they feel the warning signs of fainting.  Wearing compression stockings may help improve circulation.  Orthostatic training exercises can be helpful as well. Counter-manoeuvres such as tensing your arms with clenched fists, leg pumping, and legcrossing may stop a vasovagal syncopal episode, or at least delay it long enough that you can lie down with the feet elevated.

In some cases, a pacemaker may be necessary to help regulate heart function.



You should follow your doctor’s recommendations if you have NMS.  If you feel the warning signs of fainting, you should lie down and elevate your legs.  It is important to follow your doctor’s guidelines and attend all of your doctor appointments.

You should talk to your doctor about what triggers your fainting.  In some cases, the trigger may be avoided.  People with a family history of recurrent syncope or sudden death have an increased risk for syncope caused by a heart condition.