I went through a stage of passing out a lot when I was underweight (due to stress).
It can happen to me if my blood sugar drops through lack of food, I usually start to get really tetchy & I know I need to eat something.
I also have quite low blood pressure.
It was pretty frightening the first couple of times though, one time I passed out in a public toilet (went cos I felt funny, but had to stand in a queue) hit my head & someone phoned an ambulance & I had to go to A&E to have my head stitched! Think my friend was more scared than me though, she said I had my eyes open the whole time.
Now I know if I get that feeling to just sit down & put my head between my legs.
U.K curly

3A Curly Twirly.
Golden brown (coloured to cover grey).
Low poo: Dr Organic, L'Oreal Everpure.
Conditioner: Dr Organic Argan Oil.
Leave In: Aussie, Curl Harmony.
Gel: Curl Keeper Original, Umberto Gianni.