You probably would be surprised, but based on the thorough research I would like to note that there is no straightforward answer on seemingly simple question.
That is true, the vampires are totally fiction as they appear in popular romantic and horror fiction, are mythological beings known primarily for their reliance on human blood (and occasionally animal blood) for sustenance. While not real in a sense as actually existing as depicted, there are a few caveats that require mentioning before dismissing vampire phenomena off as a myth.
Part 1: Medical Conditions
One of the main medical conditions we would like to point a finger on is porphyria, which may cause a combination of anemia and psychological disorders leading to the belief that one must drink blood to survive.
Recent research strongly suggested that the vampire folklore might be originated from human beings that suffered a genetic disease, late in the Middle Ages. Dr David H. Dolphin, a scientist, had been researching the myth of vampires for a long while when he stumbled upon this interesting fact.
In his paper, Dr Dolphin had advanced the theory that vampires are actually normal people, who suffered from one class of incurable hereditary diseases known commonly as porphyrias, of which there are at least 8 types:
- Acute Intermittent Porphyria (AIP).
- Congenital Erythropoietic Porphyria (CEP).
- Porphyria Cutanea Tarda (PCT).
- ALAD Porphyria (ADP).
- Hepatoerythropoietic Porphyria (HEP).
- Hereditary Coproporphyria (HCP).
- Variegate Porphyria (VP).
- Erythropoietic Protoporphyria (EPP) or Protoporphyria
All porphyria disorders can be grouped by symptoms—whether they affect the skin or the nervous system. The cutaneous porphyrias affect the skin. People with cutaneous porphyria develop blisters, itching, and swelling of their skin when it is exposed to sunlight. The acute porphyrias affect the nervous system. Symptoms of acute porphyria include pain in the chest, abdomen, limbs, or back; muscle numbness, tingling, paralysis, or cramping; vomiting; constipation; and personality changes or mental disorders. These symptoms appear intermittently.
Porphyria is a slight malfunction in the bodies’ chemicals and sufferers become afflicted with the same symptoms as the fabled "vampires". Their bodies usually became grotesquely disfigured, and they had extreme sensitivity to any forms of natural/unnatural light (even the exposure to sunlight left patients' bodies with sores and scars).
Sometimes, the patients' fingers would fall off and resemble that of animal claws. Lips and gums would stretch so that the teeth would become more pronounced, of course giving resemblance to a vampire bat.
Dr Dolphin concluded that because of this, victims would only venture out at night and also may grow their hair long as it acted as protection against the deadly night. He argued that porphyria victims in the past instinctively sought the compensation for their natural weirdness by biting and sucking the blood of others. In this day and age, people suffering from this disease can simply inject themselves daily, weekly, or whenever necessary.
Porphyria, the Greek word for “purple”, is distinctive due it’s discoloration of the urine, often dark blue or purple in color. A victim of porphyria cannot produce heme, a major and vital component of red blood. Today, this disease is treatable with regular injections of heme into the body. However, as little as fifty years ago, this treatment was unavailable and the disease unknown. A common misconception was that ingesting another person’s heme (or blood) would replenish one’s own supply, but recent studies have shown this concept completely false.
Looking back on this information, we can draw the conclusion that the superstitions of our predecessors in the 'Dark Ages' could create such uproar from a genetic dysfunction. Victims suffering the disease were usually located in concentrated parts of Europe and the world, thus bringing the fabled myths and legends from Transylvania.
Another medical disorder that was often mistaken for a symptom of a vampire attack is Anemia. Derived from the Greek word for “bloodlessness”, anemia is a blood disease in which the red-cell count is unusually low. Red cells are the carriers of oxygen throughout the body. When a person suffers from anemia, their symptoms are caused by inadequate oxygen. These symptoms may include:
- A pale complexion.
- Fainting spells.
- Shortness of breath.
- Digestive disorders
There are three main causes of anemia: disease, heredity, and severe blood loss. Over the ages, a person suffering from these symptoms may have been under suspicion of a vampire attack. Although the victim may have contracted a disease or simply have inherited the blood disorder, society would have found it easy to believe that the symptoms resulted from a vampire attack, and these symptoms may even have suggested that the victim was beginning his own transition to a vampire, marked with a pale complexion and trouble eating food.
The next disorder, though much rarer than the previous one, is still very much to blame for the myth. Catalepsy is a disorder of the nervous system that causes a form of suspended animation. It causes a loss of voluntary motion, rigidity to the muscles, as well as decreased sensitivity to pain and heat.
A person suffering from catalepsy can see and hear but cannot move. Their breathing, pulse, and other regulatory functions are slowed that to an untrained eye, it would seem as though they were dead. This condition can last from minutes to days. Before 20th century medicine came along, there were few diagnostic tests that could be done on a body to ensure that a person was in fact dead, and so it is likely that persons suffering from catalepsy could have been declared dead prematurely. Embalming a corpse before burial has only been introduced in the last hundred years or so, making it very possible that these bodies were declared dead and buried while the person still lived. Upon recovering from their catalyptic state, the person would try to dig and claw their way to the surface, giving townfolk the idea that these people where rising out of their graves from the dead. Many myths may have arisen from this single condition alone.
Sleep paralysis is a condition in which someone, most often lying in a supine position, about to drop off to sleep, or just upon waking from sleep realizes that s/he is unable to move, or speak, or cry out. This may last a few seconds or several moments, occasionally longer. People frequently report feeling a "presence" that is often described as malevolent, threatening, or evil. An intense sense of dread and terror is very common.
The presence is likely to be vaguely felt or sensed just out of sight but thought to be watching or monitoring, often with intense interest, sometimes standing by, or sitting on, the bed. On some occasions the presence may attack, strangling and exerting crushing pressure on the chest. People also report auditory, visual, proprioceptive, and tactile hallucinations, as well as floating sensations and out-of-body experiences. These various sensory experiences have been referred to collectively as hypnagogic and hypnopompic experiences (HHEs).
People frequently try, unsuccessfully, to cry out. After seconds or minutes one feels suddenly released from the paralysis, but may be left with a lingering anxiety. Extreme effort to move may even produce phantom movements in which there is proprioceptive feedback of movement that conflicts with visual disconfirmation of any movement of the limb. People may also report severe pain in the limbs when trying to move them.
Physiologically, it is closely related to the normal paralysis that occurs during REM (rapid eye movement) sleep, also known as REM atonia. In that, some scientists and physicians believe it to be a "natural" effect of the sleep cycle. Sleep paralysis occurs when the brain is awakened from a REM state into essentially a normal fully awake state, but the bodily paralysis is still occurring. This causes the person to be fully aware, but unable to move. In addition, this state may be accompanied by hypnagogic hallucinations.
Researchers have pretended that sleep paralysis occurs in order to prevent the body from manifesting the sleeper's dreams which may be linked to post-synaptic inhibition of motor neurons in the pons region of the brain. In particular, low levels of melatonin may stop the depolarization current in the nerves, which prevents the stimulation of the muscles, to prevent the body from enacting the dreamt activity (ie. preventing a sleeper from running when dreaming about running).
There are some other medical conditions, which can partially explain the vampire related appearance and characteristics:
- Lupus. A chronic inflammatory disease of unknown origin, affecting many systems of the body, often characterized by a rash on the face and other areas exposed to sunlight, involving the vascular and connective tissues of many organs, and accompanied by serologic abnormalities. Essentially an auto-immune disease where your body begins to call its own tissues foreign and attack them as it would a bacteria or virus. The reaction to sunlight is caused by the bodies’ inability to recover from UV induced genetic damage of skin cells in a normal manner.
- Xeroderma pigmentosum. Only about 200 people in the United States, or two to four persons in about 1 million live births, suffer from xeroderma pigmentosum, a rare genetic defect that causes extreme sensitivity to the sun's ultraviolet rays. Ultraviolet light disrupts normal cell functioning in people who have the disorder, causing cancerous cell changes. Although there are various degrees of the disorder, most persons with xeroderma pigmentosum acquire severe sunburn after any sun exposure, although using sunscreen and layering clothes sometimes protects against the sun's negative effects.
- Pica. We all ate sand as toddlers on the playground once, but there are some people who never stop. Pica is a disorder in which sufferers have an appetite for basically everything that you are never supposed to eat: metal, dirt, sand, chalk, batteries, office supplies such as tacks, toothbrushes, soap, and certainly, drinking blood. Here’s where it gets interesting: pica is caused by a mineral deficiency, so whatever the patient is eating usually contains the mineral their body is lacking in. Pica is most commonly found in children (usually those with mental developmental disorders) and women (caused by traumatic events, OCD, or schizophrenia).
- Hematolagnia. A small minority of people are sexually aroused by drinking human blood. They have a condition called hematolagnia -- popularly called a blood fetish. This is normally considered a paraphilia, and is one of many dozens of unusual sexual interests that is often their sole means of sexual gratification. Because of the public's frequent desire to be absolutely normal in their sexual practices, people with hematolognia -- or any other paraphilia -- are often despised and even feared.
- Renfield's Syndrome. This is a disorder named after the fictional character in Dracula who ate flies, spiders, etc. Richard Noll first developed the syndrome. He believed that it is triggered by an experience after a childhood injury when the young person finds bleeding or tasting blood to be exciting. Noll wrote that the syndrome progresses to include intentional scrapes or skin cuts to allow the collection of blood for drinking. This leads to eating or drinking the blood of insects, small animals, birds, etc. This syndrome is a neat theory, but is not widely accepted by mental health professionals. It does not appear in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).
So, many theories for the origins of vampire beliefs have been offered as an explanation for the superstition, and sometimes mass hysteria, caused by vampires. Everything ranging from premature burial to the early ignorance of the body's decomposition cycle after death has been cited as the cause for the belief in vampires.
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