Why can a wave of gas pain or bout of diarrhea make a person suddenly feel like they are about to pass out? Or cause them to sweat?
In: 9
Vasovagal Syncope is when the vagus nerve is stimulated during something stressful, or something that causes anxiety. Common examples being: seeing blood, seeing needles or getting a shot, having a bowel movement.
When under stress, your heart rate slows and the blood vessels in your legs expand. This causes blood to pool in your legs, which if you were running would help supply oxygen to your muscles and escape predators. It is a response built into our bodies, a quirk of evolution.
Now when you get stressed, if you happen for some strange reason to *not* be running from a tiger, it becomes a ‘maladaptive response’ (I.E. an action by the body which harms you rather than helps).
The blood pooling in your legs removes oxygen from where you need it (principally your brain), especially if you already have low blood pressure because of dehydration or poor health. This causes nausea, fatigue, clammy skin, blurred vision and in extreme cases fainting.
Source: National Library of Medicine; [The origin of Vasovagal Syncope](https://pubmed.ncbi.nlm.nih.gov/18592129/)
Latest Answers