When I was 16 I was skateboarding and I fell and hit my head on the cement, I stood up and my hearing went away and my eye site and I blacked out with my eyes open. Then a year later I was at the gym doing a light leg workout and the same thing happened, I had to run to the locker room with no vision and make it to the bench and lay down. A year later I was at a concert, I had been standing all day and I looked at my boyfriend and it happened again except this time after I woke up, I threw up everywhere. Today at the gym with my new trainer the same thing happened. Does anyone know what this could be?? I get migraines and joint pain but besides that nothing else normally.