On Vampire Physiology (updated 20 Sept)

On Vampire Physiology

Blood Basics:

Vampires and humans could be thought of as two cars running on different fuels. Thus a vampire’s body operates in the same way as a human’s, much as cars work in the same way at a mechanical level. The difference is in how physical needs are met; humans must eat for nutrients, while a vampire’s needs are met entirely through the blood. They do not need additional nourishment of any kind to supplement their body; in fact, the blood manages the functions of the body quite effectively, allowing for rapid regeneration of cells. Vampires are physically capable of eating, but it does nothing for them physically. They do occasionally need to breath, both in order to speak and to give oxygen to the blood, but not as often as humans.

Blood Replication

Despite their similarities to humans, vampires are in fact a different species. When a human is turned to a vampire, their blood is completely drained and replaced with their new source of life, their creator’s blood. As such, they cannot procreate by human methods. They reproduce entirely by turning humans, and have no way to create new life.

Blood Flow

The human body already has a quite convenient way of moving blood through the body, and vampires use this system as well; thus a vampire’s heart beats and blood moves through his veins. However, in addition to the human circulatory system, vampires have a close connection to their blood, and are able to focus and direct it in order to heal wounds, offer their blood to others, etc. This is not an entirely conscious act, though with focused effort a vampire can heal themselves even more quickly than they would normally.

Blood Thirst*

It takes many years for a vampire to learn how best to use their blood to its maximum efficiency. Therefore, feeding needs vary from a few days for the youngest vampires to up to a month for ancients, though excessive thirst will alter this need accordingly. After this point, a vampire begins to starve, which is a very slow, very painful process that gradually renders the body and vampire abilities useless. At the end of this process, the vampire either dies, or slips into a coma.

Vampires with a high level of control over their blood (ancients/older vampires) may push themselves into a "vampire stasis" when they are dangerously low on blood. In this coma-like state, they function at an absolute minimum and consume the least possible amount of blood. Keep in mind that blood is still being consumed, albeit slowly, so they will dry out eventually. Younger vampires with weaker control over their blood may be able to enter this state for a shorter duration, and would not be as efficient with their blood use.

Even with these measures, a vampire will eventually need blood replenishment, however if they get even the smallest amount of fresh blood while in this state, they can continue their coma sleep. The mental side effects of this state vary by age and duration of sleep, though there would always be consequences. They range from going insane to going completely brain dead as the brain is deprived of blood. The maximum duration for the coma sleep is ten times the amount of time a given vampire could typically last without feeding.

Vampires require around a pint of blood to have their needs met. Drinking more than they need has the same effect as eating a large meal would have on a human; contentment, but no real benefit. They will still have to feed on schedule. They may require more blood from a sickly source, or less blood from another vampire. (Though they can obtain nourishment from other vampires, there is an obvious perpetual motion problem with doing so.)

Bite Marks
When a vampire is on the hunt, they release pheromones that intensify as the vampire approaches prey and bites. This makes the vampire bite a uniquely euphoric experience, though much still depends on the vampire and the prey in question. There will be a slight initial pain for the prey but such things can be quickly forgotten under the influence of a typical bite and the prey would have to be resisting in order for the pain to continue. Likewise, if the vampire intends to cause pain in their prey, they would have to be rough enough to override the naturally pleasurable sensation of the bite.

In addition to the pheromones released during hunting and biting, a vampire’s saliva contains enzymes that are unique to each individual. These enzymes come into play during turning and familiar bonding and do not effect the sensation of the bite, though they do contain a healing agent that causes the bite marks to heal rapidly, leaving behind only a bruise in a short amount of time.

To clarify, while there are certain chemical reactions at play during a bite, it is largely up to the vampire and the prey involved to determine how the bite feels in a more specific context.

Blood Types

There are three sources of blood for a vampire to choose from; vampire, human, and animal. Each have their own strengths and weaknesses. Vampire blood is the most fulfilling but also the least convenient to obtain. Animal blood is easy to acquire and gives those vampires concerned with such things a clear conscience, but has the disadvantage of being the weakest of the bloods, and is not generally considered pleasant tasting. Human blood is a middle ground of sorts; not as powerful as vampire blood but satisfying enough to suit most vampires.

Blood Taste

The taste of blood depends on both the vampire and his ‘victim.’ Vampire blood is considered more ‘rich’ than human blood. Emotions, body chemistry, time of day, temperature, diet, drug and alcohol use, and any number of other factors make each feeding a unique experience. Blood in general has a pleasant taste to a vampire, though poor health or excesses in diet or drugs leave an aftertaste that reflects these flaws.

Blood Works

Having vampire blood has the result of using one’s body to its full potential. Vampire strength is not a universal measurement across the board; the more muscle a vampire has, the stronger she will be, but if one compared a human and a vampire of the same build, the vampire would have approximately three times the strength and speed of movement. Cells regenerate much more rapidly than a human’s, meaning wounds heal before one’s eyes. Less rest is required of a vampire as compared to a human, particularly when they are well fed, though they still need some sleep in a twenty four hour period to function at optimum. Beyond that, the blood provides specific abilities that vary from vampire to vampire.

Again, these enhanced physical and mental qualities are the result of the blood, meaning if they were to go hungry or bleed heavily, their abilities and enhancements would fade.

Blood Sense

Vampire senses are heightened; they have improved sight, particularly at night (though it’s nothing to a pair of night vision goggles), their hearing is more sensitive, and they can rely somewhat more on their sense of smell, particularly the smell of blood.

They do not have any innate ability to “sense” other vampires, nor do they have a natural “sixth sense” of any kind. Any methods of identifying other vampires are either social (via conversation), cultural (via “signals” that make them recognizable to their clansmen or their kind in general) or a result of their specific abilities.

Blood Sickness

The blood causes unique weaknesses in each vampire, ranging from varying forms of madness to physical difficulties, in addition to some universal vampire qualities. UV rays from the sun cause a burning reaction in the blood, essentially boiling a vampire from the inside out. With many years and practiced control over the blood, a vampire may be able to enjoy the sunlight for a very short time, but eventually it will take its toll. Sunlight and fire has an additional risk for vampires; vampire blood is consumed rapidly by natural light and flame. Thus both fire and sunlight are shunned by vampires.**

A stake to the heart forces a vampire to direct the blood on his own, which depending on the vampire's age and innate abilities can have effects ranging from immobilization to discomfort. It would, however, typically take more than a stake to actually kill a vampire.

A vampire’s body can in no way be sustained without their blood, and the final phase of death for a vampire is the complete disintegration of their body once the blood has left them. Whether the blood has been consumed from the inside by sunlight, burned down by fire, or lost due to injury, the body will fall to ash without it.

Blood Combinations

Human blood and vampire blood combined has, predominately, a euphoric effect on both species. Vampires in general find feeding to be a pleasurable experience, and humans can get an intense high from drinking vampire blood. However, for humans to drink vampire blood is to introduce something much more foreign into their system than the other way around. While drinking vampire blood will not turn a human, said human will taken on a greatly reduced form of vampire strengths and vulnerabilities. They can also become powerfully addicted to vampire blood in a very short span of time.

Blood Bonds

A vampire’s bite has the added effect of potentially creating a unique bond with humans. Unlike the vampire bonding ability, this relationship is one of loyal subservience on the part of the human, the result of which is what vampires call a familiar.

The familiar bond is initially created when a vampire bites a human three times in as many days. It must be reinforced via biting as frequently as the vampire needs to feed. A vampire does not have to drink its fill from the familiar (as in the case of younger vampires this would likely kill the human), but the familiar must be bitten or the bond will fade.


[Thank you Aron!]


On Human Blood Loss: Plasma (non-blood liquid) volumes will return to normal in around 24 hours, while red blood cells are replaced by bone marrow into the circulatory system within about 3-5 weeks, and lost iron replaced over 6-8 weeks.

The American Red Cross limits blood donation times to once every 56 days.
[Wikipedia.Org | Thank you Connie!]