Doctor Oz was asked by Dan, a man in the audience, why do people get queasy or pass out from seeing blood?
Dr. Oz said that 15% of Americans will pass out because all of their blood will go to their legs and they will collapse. Interestingly enough, Dr. Oz pointed out that in battle, this is actually a great survival mechanism. If everyone around you is getting shot and killed, and you pass out from seeing blood, your enemy may think you are dead when really you are just passed out. Very interesting!