From Wikipedia:
Also,
http://en.wikipedia.org/wiki/Vampire_lifestyle
http://en.wikipedia.org/wiki/Porphyria
Discuss.
http://en.wikipedia.org/wiki/Clinical_vampirismRenfield's syndrome, also called simply Renfield syndrome and traditionally known as clinical vampirism, though not currently categorized in the DSM-IV, is a mental disorder used to describe an obsession to drink blood. The term was first coined by Richard Noll and is named after Dracula's insect-eating assistant, Renfield, in the novel by Bram Stoker. The term has been used in both psychiatric and fictional literature, as well as on television, where it was briefly mentioned in an episode of CSI titled "Committed" (Season 5, Episode 21).
People who suffer from this condition are primarily male. The craving for blood arises from the idea that it conveys life-enhancing powers. According to Noll, the condition starts with a key event in childhood that causes the experience of blood injury or the ingestion of blood to be exciting. After puberty, the excitement is experienced as sexual arousal. Throughout adolescence and adulthood, blood, its presence, and its consumption can also stimulate a sense of power and control. Noll explains that Renfield's syndrome begins with autovampirism and then progresses to the consumption of the blood of other creatures.
Also,
http://en.wikipedia.org/wiki/Vampire_lifestyle
http://en.wikipedia.org/wiki/Porphyria
Discuss.