Hemophagia, the consumption of blood (actual, or a desire that persists and is disturbing) is often a sign of a more serious underlying condition.
You can spot one such condition quickly. When you next urinate, wait a few minutes before flushing. If the urine slowly turns to a color that can be mistaken for blood, you have one form of porphyria; if not, you may still have other forms, or some other condition.
Your best bet is to make an appointment with a psychiatrist, who can then proceed with a differential diagnosis, or send you on to an endocrinologist.
If you decide that you absolutely MUST consume blood, you should cook it first. The US Armed Forces Survival Manual states succinctly that raw blood will likely make you sick, so it should be mixed equally with water and boiled for at least a minute to prevent vomiting and to kill parasites and pathogens.
Beef and pork blood should be available from a butcher shop inexpensively--tell them you want to make blood pudding.
- according to a psych nurse from this
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