Summary- Why do vampires need blood? Edit
It's simple. Many people say that vampires need blood because it is their main source of nourishment that they need in order to survive. It keeps them functioning just as if certain foods and ingredients keep humans nourished. The word vampire itself means "blood sucker". Vampires have also been associated with the term Porphyria which also plays a big role in why vampires are known to need blood. Porphyria is a disease that causes weird, irrational behavior, paleness and the desire to ingest blood. The vampires are said to be dead, or "un-dead" which is why they are cold to the touch, so that means that they are incapable of creating blood so that is why the must resort to sucking the blood from other things like humans and animals. Receiving this blood from other sources replenishes the supply of oxygen back into the muscles. This explanation is much more scientific than the one that I first stated, being a lot more credible.So why are vampires known to suck blood from the neck? Some sources say that the reason for this is because the main jugular vein is located in the neck. I think of blood to vampires, is how water is to us humans. We cannot survive totally with out it, but we do not need it constantly, at all times.