Do Vampires really exist? Myth, fake new, or is there really some truth to sucking blood?

The origin of Vampires and Folklore.

This is a brief history of Vampires. Vampires are nearly as old as humans. Vampires appear in cultures extending as far back as prehistoric times. But they weren't called vampires back then and most of us did not look the way we imagine vampires today. For example, the Mesopotamian Lamashtu was a creature with the head of a lion and a body of a donkey and the ancient Greek Striges as were simply described as bloodthirsty birds. Other were even stranger. The Philippine Manananggal would sever her upper torso and sprout huge bat-like wing to fly. The Malaysian Penangggaln was a flying female head with dangling entrails and the Australian Yara-ma-yha-who was a little red guy with a big head, a large mouth, and bloodsuckers on his hands and feet to name an example. Though they may look different all of these have one common characteristic they sustain themselves by consuming the life force of a living creature. This shared trait is what defines a vampire. Our modern idea emerges in the 18th century Eastern Europe. With the dramatic increase of vampires superstitions, stories of the bloodsucking, shadowy creature become nightly bedside terrors. And popular folklore, like the Moroi among the Romani people and the Lugat in Albania, provide the most common vampire traits know today, such as vampire being undead, nocturnal and shapeshifting. Eastern Europe in the 18th century was a pretty grim place with many deaths occurring from unknown disease and plagues. Without medical explanation, people searched for supernatural causes and found what looked like evidence in the corpses of the victims. When villager dug up bodies to discern the cause of the mysterious deaths, they would often find the cadavers looking very much alive longer hair and fingernails, bloated bellies, and blood at the corners of mouths. the people think they are vampires but that was actually normal symptoms of death. When a body decomposes, the skin dehydrates, causing the hair and fingernails to extend. Bacteria in the stomach creates gases that full the belly, which forces out blood and matter through to the mouth. The vampire doesn't exist but is there really some truth to sucking blood in the real world.

The animal that sucks blood   

Leech: Most people avoid these bloodsucking worms, leeches have long been used in the world of medicine. Into the 19th century, leeches were used to treat such conditions as mental illness, tumours, skin disease, gout, and whooping cough. While those treatments are now discontinued, leeches have found new and proven uses in modern medicine. Most notably, leeches are used to restore blood flow to damaged veins after an appendage is reattached or a tissue grafted. 

Vampire bat: This type of bat, of which there are three species, is the only known mammal whose diet is solely based on blood. Although livestock, birds, and reptiles are its typical targets, humans are occasionally its prey. Vampire bats which must feed at least every two days use razor-sharp teeth to make tiny incisions in their victims and then lick the flowing blood. The satiated bats will often regurgitate blood to share with those who are hungry. 

Why do some animal suck blood?

This behaviour is called Hematophagy from the Greek word haima meaning blood and phagein meaning to eat. Animal evolved this because blood is rich nutritious protein and lipids that can be taken without great effort.