What might be the cause/causes of a blackout? I am 68 yrs old, reasonably healthy, with no diagnosis of any heart or brain problem, but recently woke up from a blackout with no clue as to the cause. I have been to a brain clinic and other doctors so far, but they are not telling me anything about what happened to me, and are saying there is nothing wrong with me. I don t believe them I m sorry to have bothered you. I did not realize there was a fee to ask a question, but I do understand. right now, I don t even have sufficient funds to pay for a phone, so I need to be vrey cautious of how I spend the $$ I do have. thank you anyway,