SCIENCE - Halloween Issue
Science explains the truth behind the myth: "vampire" disorders
There's no doubt that vampires capture our imaginations; recent obsessions with "Twilight," "True Blood" and The Vampire Diaries prove it. In the past, people truly believed in the existence of vampires - perhaps for good reason.
While there is no scientific evidence that vampires actually exist, there are several medical conditions that result in vampire-like features and behaviors. Historic misinterpretations of these conditions have formulated the vampire myth we know and love today.
One mistaken display of vampirism is a condition known as catalepsy. As a symptom of Parkinson's disease, epilepsy and schizophrenia, catalepsy is primarily characterized by muscular stiffness and a fixed posture.
During a cataleptic episode, a person's heart rate and breathing may slow to the extent that neither are detectable through simple medical examinations.
Because a cataleptic episode can last hours, or even days, people used to believe cataleptics were dead and would mistakenly bury them alive. When some of these buried individuals came to, they would dig themselves out of their graves, giving the impression that they had literally come back to life.
To make things worse, some of these individuals also suffered from mental disorders such as schizophrenia and behaved quite strangely after "awakening."
Another vampire-like disease, known as porphyria, is a condition characterized by decreased amounts of heme, the iron-rich red pigment in blood.
People with extreme cases of porphyria are highly sensitive to sunlight and can sometimes become delirious. Sufferers also have reddish mouths and teeth.
Because drinking blood alleviates some of these symptoms, namely by balancing heme levels, this practice worked its way into the vampire myth as well. Furthermore, because porphyria is a hereditary disease, descriptions of these "vampires" have historically been concentrated in specific areas.
Sufferers of Gunther's disease have reddish eyes and skin, a receding upper lip and cracking of the skin when exposed to sunlight. These features may seem supernatural, but they are ultimately medical symptoms.
In some places, a common practice among suspicious villagers was to exhume the graves of "vampires" a few days later and look for vampire-like characteristics. Often, the hair, teeth and fingernails would appear to have grown and the bodies would still have blood in the heart, leading to beliefs of vampire immortality.
In reality, every decomposing body will have protruding fingernails, hair and teeth as the skin dries and recedes. Blood in the heart can be attributed to the normal processes of postmortem decomposition as well.
As for what kills vampires, there is no basis for the stake through the heart, fire, beheading, holy water or garlic. These were actually the inventions of "Dracula" author Bram Stoker, and most of them would kill any normal non-vampire.
Likewise, a vampire's ability to radiantly sparkle is entirely made up by Stephanie Meyer. Although, that does make for an attractive Edward Cullen...