cold sweats, nauciousness, tunnel vision & passing out

in the past few months i've had this happen to me a few times. out of nowhere, i will start to feel naucious and get cold sweats, and start to feel weak. then my vision sort of fades to black and when it does i collapse. ill pass out for a minute or a few minutes, and when i wake up i feel fine for the most part. my first thought was low blood sugar, but this has happend right after eating one time so i dont know what it is. the 2nd time i fell and cut my head open because i smashed it so hard and it happend again today. i worry that this will happen when i am driving or something, does anybody know what some possible causes for this might be?

[Wati_Feir]

Something very similar keeps happening to me. I think it's called vertigo, but I can't confirm as I'm not good at matching it to descriptions. Basically my ears drown out making me lose balance, I collapse and lie there conscious, feeling sick for a minute or two.