Cause
Vasovagal syncope occurs in response to a trigger, with a corresponding malfunction in the parts of the nervous system that regulate heart rate and blood pressure. When heart rate slows, blood pressure drops, and the resulting lack of blood to the brain causes fainting.
Typical triggers for vasovagal episodes include:
- Prolonged standing or upright sitting
- Standing up very quickly (Orthostatic hypotension)
- Stress directly related to trauma
- Stress
- P.O.T.S.(Postural Orthostatic Tachycardia Syndrome) Multiple chronic episodes are experienced daily by many patients diagnosed with this syndrome. Episodes are most commonly manifested upon standing up.
- Any painful or unpleasant stimuli, such as:
- Trauma (such as hitting one's funny bone)
- Watching or experiencing medical procedures (such as Venipuncture)
- High pressure on or around the chest area after heavy exercise
- Myocardial infarction, severe valvular (sic) disease, and disturbances in rhythm which reduce the output of blood may be responsible
- Severe menstrual cramps
- Arousal or stimulants, e.g. sex, tickling or adrenaline
- Sudden onset of extreme emotions
- Lack of Sleep
- Dehydration
- Hunger
- Being exposed to high temperatures
- In health care, such as nursing care, digital rectal procedures (e.g., digital disimpaction)
- Random onsets due to nerve malfunctions
- Pressing upon certain places on the throat, sinuses, and eyes (also known as vagal reflex stimulation when performed clinically)
- Use of certain drugs that affect blood pressure, such as cocaine, alcohol, marijuana, inhalants and opiates
- The sight of blood or blood drawing
- Violent coughing
- Serotonin level / SSRI
- Swallowing
- (Less commonly) Low Blood Sugar
Read more about this topic: Vasovagal Response