Syncope, commonly known as a “black out” or “fainting”, is a brief loss of consciousness as a result of a sudden drop in blood pressure and decrease in heart rate which results in an insufficient flow of blood to the brain. Some people collapse after an episode but most people regain consciousness after a few moments, but they may experience a state of confusion for a short period.

What causes Syncope

When the heart rate slows down and the blood vessels in the legs enlarge, blood begins to pool in the legs. This causes blood pressure to drop and with a slowed heart rate, there is less blood flow to the brain. There are many different causes of syncope, which may include:

  • Poor blood circulation
  • Nervous system malfunctioning
  • A change in the blood pressure
  • A change in heart rate
  • Stress
  • Pain
  • A change in body position
  • Overheating
  • Dehydration
  • Exhaustion
  • Side effects of certain medication

Fainting may be caused by a variety of medications, diseases, and conditions, but it isn’t caused by a head injury, which is considered a concussion.

Some causes of fainting can be a warning sign of a life-threatening situation. Usually, fainting is a relatively common condition and is not life-threatening.

Most fainting spells can be easily explained, but some people never get a diagnosis or know the specific cause of the fainting spells.

Symptoms of Syncope

Patients with syncope may experience the following:

  • Light-headedness
  • Dizziness
  • Drowsiness
  • Unsteadiness
  • Pale skin
  • Tunnel vision
  • Nausea

Patients may experience heart palpitations or a warm feeling before a fainting episode as well, which become warning signs that patients can recognise before syncope occurs. After an episode of syncope, at least 30 percent of patients will have a recurrence.


Because fainting can be an indication of another condition, a patient should alert their doctor about their episode. Treatment for syncope depends on the underlying cause of the condition, and the aim is to prevent more fainting episodes. Treatment may include:

  • Medication
  • Support garments to improve circulation
  • Biofeedback training
  • Pacemaker, to regulate the heart rate
  • Foot exercises
  • Dietary modification

This article is intended to inform and give insight but not treat, diagnose or replace the advice of a doctor. Always seek medical advice with any questions regarding a medical condition.