The first step in understanding vampire lore is to understand some of the biological reasons that may have led to such beliefs. One of the most plausible explanations for vampire myths is the disease porphyria, which occurred frequently in Transylvania. Porphyria is a blood-related condition where a vital function of blood cells is lost. This results in rapid tissue damage, giving the victim a ghastly pallor and enlarged teeth due to gum damage. The effects of porphyria are greatly amplified upon exposure to the sun, making sun light a likely threat victims would try to avoid at all costs. It is also believed that certain strains of porphyria are associated with neurological conditions, which would result in insanity. This condition also explains the practice of drinking blood, as these people would likely drink animal blood as a cure for the anemia associated with porphyria. Another explanation for this legend is the disease rabies, as it leads to hypersensitivity, unusual sleep patterns, and intense sexuality. Rabies is also associated with the compulsion to bite others, and a bloody foaming at the mouth. These two diseases could possibly explain the origins of such legends, and perhaps also why they are so widespread.
From the beginning of history, vampire-like spirits and beings have been recorded. The Akhkharu were blood-sucking demons, written about back in the time of Sumer. The ancient Chinese wrote about “hopping corpses” which would go around and consume a victim’s life essence (commonly known as chi). Even ancient Egyptian lore had a story where the goddess Sakhmet was consumed with bloodlust. From the earliest of times, these beings have been prominent in folklore from several different cultures.
The most well-known versions of such myths are those of the Slavic and Romanian cultures, which, due to their proximity, are surprisingly similar. Both have several reasons that a person may become a vampire, such as unnatural death, birth defects, or conception on certain days. Romanian legend gave rise to the belief that being bitten by a vampire would doom one to become a vampire after death. Both Slavic and Romanian myths hold the belief that, with the advent of a vampire, there would be deaths of livestock and family members of the vampire. The favored way to kill a vampire in these two myths is by driving a stake through the heart, decapitation, and if necessary, dismemberment. Slavic and Romanian vampire myths have given rise to the most popular world-view of vampires.