Vasovagal Reaction
The vasovagal reaction is a condition [6] in which a healthy person develops sudden and short-term hypotension. Common symptoms of this condition include slow heartbeats, lightheadedness, and fainting. This reaction is usually caused by intense emotions of fear or pain. It is involuntary and takes place in the nervous system, where there’s a release of hormones in the vagus nerve that slows the heart rate and widens the blood vessels. A few people also have a vasovagal reaction from straining while defecating or vomiting.
Micturition Syncope
Micturition syncope is a sudden and temporary fall in blood pressure, usually during urination, and it is often accompanied by short-term loss of consciousness. Elderly persons are at a high risk of experiencing this condition, which may be due to the release of hormones that lower blood pressure.