I never ever had a problem with blood before.
Then many years ago (maybe 8?) I was checking out yard sales with my mom, picking stuff up and looking at it, etc. After one stop, we went back to the car, and I noticed that there was blood on my thumb. It didn't feel like I was cut, or that it was much. So I went to suck it off. It was until after I sucked, that I realized it was a whole glob of blood, which was now in my mouth and I had no choice but to swallow because I was in the car. Yuck. So then at our next stop, I get out and as I'm crossing the road, my vision went completely negative, and then black and white and tunneled - I turned around and stumbled back to the car just barely, and laid down in the back seat. It was the weirdest experience I ever had - I think my body must have gone into shock and started pooling blood towards the center, and my eyes were left without a blood supply.
Ever since then, blood makes me nauseus and dizzy. Aside from my blood phobia, I also have a problem with needles.