Why do I always pass out?

Why sometimes when I stand up from sitting or laying down, I all of a sudden feel lightheaded, loose my balance and pass out on the floor for literally about 10 seconds then get back up feeling just fine...??? WHAT THE HELL IS THAT???

This sounds like what doctors call orthostatic hypotension.

When you lie down you head is at about the same level as your heart so it takes less blood pressure to get blood to your brain than when you are standing and the blood has to be pumped upward. When you get up quickly it takes a moment or two for your body to adjust your blood pressure to continue to get the same amount of blood to your brain. When you go from sitting to standing the blood pooled in your lower extremities has to be pushed back up to your heart and until your body adjusts it doesn't have the pressure to do this immediately.

Most people learn how quickly they can get up without any drama. We subconsciously adjust our behavior so our blood pressure can catch up with us. Dehydration, anemia, fatigue and other conditions can exaspirate this normal drop in blood pressure and catch us off guard.

Sounds like either low blood pressure or not enough oxygen in your blood. I'd see a doctor if I were you.

Definitely see a doctor about this, I think it would be because of blood pressure changes when you begin to move. Some times our blood pressure drops and gives you the light headed feeling and if there isn't enough oxygen still in your blood then fainting may happen.

But definitely see a Doctor is this is happening regularly

low blood pressure?
anaemia?
not eating enough?

I think the explanation might be orthostatic hypotension. You can find more information here: http://www.medterms.com/script/main/art.asp?articlekey=4672