So tonight I went out with some friends to the bars and I had 4 beers. Granted I don't drink a lot, but I'm a kinda big guy at 6'3" and I work out. I drank the beers over 2 1/2 - 3 hrs. and then I smoked a bowl when I got home. So I'm chillen pretty high and feelin those beers. An hour or so later I go to the bathroom. Now normally when I stand up I get light headed, I've done some research and believe its because I work out and my heart is in good shape so it beats slower and takes longer to get blood to my brain after I stand up. I get up and I start walking and I feel the light headedness coming and my vision goes but I'm able to stay up. I go on thinking I dodged a bullet. I get to the bathroom and pee. And then I think I sat down to poop and just have a nice sit down (I can't remember if I was starting to feel bad while I was peeing or not). Any ways I stand back up to wash my hands and get outta there, and then I feel another light headedness coming. I stay standing thinking I can take this one too! My vision goes. I look into my eyes in the mirror. Its as if I'm looking into some completely other persons eyes. BAM! Buh-BOOM! Next thing I know I'm getting off the ground, hearing my mom ask if I'm ok, and I say "yea yea" and start picking up the the shit I knocked over. Now I'm turning to you, in the science forum, to help me diagnose this situation. This has happened to me once before. I went to a bar and I had about 3 drinks before. I got to the bar and I got hot and passed out. It doesn't happen all the time I drink though. I think it has something to do with my circulatory system. What will alcohol do to your blood, blood vessels, or heart muscle?