Causes of Fainting
Simple Causes: There are a number of simple and everyday causes of a faint.
- Standing for long periods of time, especially in the heat.
- Heat exposure (heatstroke)
- Dehydration. This can lead to low blood pressure and then to fainting.
- Pregnancy. Some feelings of faintness are common in pregnancy. But see your doctor about it if it seems serious.
- Emotional stress. Some people can feel faint when they experience emotional stress or a sudden shock.
- Vertigo (Giddiness). This is the dizzy sensation of the room spinning, which can cause a person to fall down like fainting. There are various causes of vertigo. Read more about: Vertigo, Dizziness.
- Medications. Some medications cause vertigo or low blood pressure (and hence fainting) as a side-effect.
Disease Causes: Fainting can indicate a more serious underlying disease. Some of the diseases where fainting or feeling faint may be a symptom include disorders of blood pressure, heart disorders, metabolic diseases, and other causes.
- Hypotension (low blood pressure). There are various causes of low blood pressure, including certain types of disease and reactions to medications. Read more about: Low Blood Pressure.
- Postural Hypotension (Orthostatic Hypotension). This refers to having low blood pressure when you stand up from sitting or lying down (or attempt to stand up), or with other posture changes.
Metabolic Causes: Various issues with the body’s metabolism can cause fainting:
- Hypoglycemia (low blood sugar). Low blood sugar can lead to faints. There are various causes of hypoglycemia.
- Diabetic hypoglycemia. When a diabetic has a “hypo” or an “insulin attack” it can lead to low blood sugars, and to fainting.
- Stroke. A medical emergency which can cause faintness or similar symptoms.
- Transient Ischemic Attack (Mini-strokes). These are “mini-strokes” that seem to come and go. Did the person have symptoms like those of a stroke, but the symptoms have now disappeared? These attacks are also a medical emergency as they often progress to a full stroke.
- Unconsciousness. Is it more than a simple faint? More than a momentary loss of consciousness? Was the person unconscious for a long period of time? It could be something more serious than a simple faint, such as Concussion, Head Injury, or other brain disorder. Note that if a person actually falls during a faint, they might actually sustain a head injury from the fall.
- Cervical Spondylosis. A disorder of the vertebrae in the neck, which can cause faintness, especially if the feeling of faintness occurs when moving the neck or head.
- Carotid sinus hypersensitivity
- Heart Disorders
- Heart Rhythm Disorders
- Adams-Stokes Attack. This is a slowing of the heartbeat, which can cause attacks of faintness.
- Low blood volume (Internal Bleeding, Bleeding in the Digestive Tract). This can cause low blood pressure. Do you have any signs of internal bleeding? Or signs of bleeding inside the digestive tract? Rectal bleeding? Blood in the stool, or black, darkened stool. Vomiting blood? Any bleeding?
- Aortic stenosis
- Aortic insufficiency
- Mitral stenosis
- Mitral valve prolapse
Other Causes: Various other causes of fainting or faint-like episodes include:
- Psychogenic syncope
- Intentional breath-holding (e.g. children’s tantrums)
- Medication side-effects
- Medication interactions
Similar Symptoms: See also causes of symptoms similar to fainting:
- Balance symptoms
- Decreased level of consciousness
Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.