Hello! i have had two situations now where i seem to black out while sitting, once while at the doctor's office and once while driving. very scary.

Black out: a blackout usually implies a disturbance of brain function, either due to something wrong in the brain or due to loss of adequate blood flow through the brain. In either event UR at serious risk of unheralded recurrence with the potential for serious attendant injury including death. Stop driving or operating machinery, exposure to hostile environment EG swimming erc till diagnosed & treated