What are the causes of fainting?

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Fainting or syncope is simply brief loss of consciousness. This is usually brought about by a momentary loss of blood flow to the brain and might be an indication of a serious health condition. Individuals of any age can faint but among the elderly, it might have a serious underlying cause.

The usual causes of fainting include vasovagal and heart conditions. On the other hand, several cases of fainting do not have a specific cause.

Causes of fainting

Vasovagal syncope

Individuals of any age can faint but among the elderly, it might have a serious underlying cause.

This is commonly called as the “common faint” which is the usual cause of fainting which is due to an erratic circulatory reflex. The heart pumps forcefully and the blood vessels are relaxed, but the heart rate could not compensate enough to maintain the flow of blood to the brain.

Individuals older than 45 years rarely experience an initial “common faint”. The usual causes of vasovagal syncope include:

  • Emotional factors such as stress or danger of injury
  • Environmental factors such as crowded areas or hot environments
  • Physical factors such as prolonged standing
  • Conditions such as dehydration, fatigue or other illnesses

Postural syncope

This occurs if an individual lying down quickly faints upon standing up. The flow of blood to the brain drops once the individual stands due to a brief decrease in the blood pressure. This oftentimes occur among those who recently started or changed heart medications.

Cardiac syncope

Certain heart conditions might be the cause due to various mechanisms. The cardiac causes of fainting are life-threatening and includes the following:

  • Cardiac obstruction
  • Irregularities with the heart rhythm (arrhythmia)
  • Heart failure

Neurological syncope

This type can be triggered by a neurological condition or any of the following:

  • Stroke can cause fainting linked with a headache
  • Transient ischemic attack can be a cause that is usually preceded by balance loss, double vision, slurred speech or vertigo.
  • Migraines

Psychogenic syncope

Hyperventilation due to an anxiety disorder can result to fainting. In rare instances, some individuals pretend to faint to reduce stress. A diagnosis for this type of syncope must only be considered if all other causes have been excluded.

Quick Note / Disclaimer

The material posted on this page on fainting is for learning and educational purposes only. To learn to recognize and manage sudden emergencies including fainting due to a serious underlying cause, register for a first aid and CPR course with Red Deer First Aid.

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