Why would someone have a headache after a vasovagal syncope?

Answer 1

Vasovagal syncope means that your parasympathetic nervous system (which calms and quiets your body) kicked in too strongly, causing a drop in blood pressure. This drop in blood pressure causes a lot of things to happen, two of which are fainting (syncope) and headache. The drop in pressure changes the pressure in your head as well, and the membrane surrounding your brain is sensitive to such pressure changes, and generally causes pain in the form of a head ache. When people take nitro for heart pain, the result is a drop in blood pressure, usually with an accompanying headache.