I am wondering because my younger twin son is apparently now "prone to fainting" (funny, I thought he was prone *because* he fainted, but hey), having once, in 4th grade during a concert in which he was singing, fainted off the stage from not moving his feet enough, and now he just fainted again in the hospital cafeteria where I work (in the hospital, not the cafeteria). He had had breakfast and drunk water just before biking the 2-3 miles to see me for lunch in very hot weather, went into the cafeteria to buy lunch, and fainted onto his face, taking a cereal tree with him. All is fine fine fine, but I'm curious. YES we went to the ER, he is really fine fine fine. But...
I used to faint at needles - not shots, but anything involving my venous system. I could faint when they shot stuff into my IV tubing, let alone when the IV went in. I don't anymore but from age 10 to about 35, I knew better than to try to do anything like that without lying down first. Then it just stopped, and now I don't even get dizzy... so again, I'm curious.