So this is a bit of a strange question really, but at the same time it is somewhat logical to think you could do this.
At the very least, one would assume that drinking blood may be safer than drinking your own urine to stay hydrated.
Before we talk about whether or not blood would hydrate you, we’ve got to first think about whether it’s safe to actually drink at all!
Is it safe to drink your blood?
In very small amounts, like a few teaspoons, drinking blood is absolutely safe.
Well, so long as it’s clean blood that doesn’t carry any crazy pathogens or weird jungle diseases or whatever, but that goes without saying.
However, past a few teaspoons, a human’s blood can actually be pretty damn toxic to drink.
This is because blood is so rich in iron and the body has great difficulty excreting this excess iron.
Too much ingested blood will lead to hemochromatosis, which will give you anything from liver damage, to low blood pressure or nervous disorders all the way through to excessive fluid building up in your lungs and drowning you to death from the inside. Lovely.
Is it safe for animals to drink their blood?
Now this is the case in most animals as well as people, although there are exceptions like the vampire bat, of course.
For animals that have blood as a staple feature in their diet, their digestive systems have adapted to cope with the excess iron over several millennia of constant evolution.
Using the vampire bat as an example (I mean, it’s got “vampire” in its name, is there a better example?), this animal has evolved to have a high dietary requirement for iron.
The iron a vampire bat gets from its victims helps make hemoglobin for carrying oxygen from the lungs to the body tissues.
Even so, a vampire bat will still take on more iron than it needs when it feeds, and as such it has a special process for secreting the surplus iron.
When ingested, the blood will go through a tract adapted for extracting nutrients.
Vampire bats have a specialized mucous membrane along their intestinal tract which blocks too much iron from getting into the bloodstream – thus keeping them safe from the potential health impacts.
Does drinking animal blood hydrate you?
Drinking animal blood has helped people in the past, like ocean castaways who have eaten turtles raw and drank their blood.
Although the flesh of the animal will hydrate you far more than its blood ever would.
Does drinking your own blood hydrate you?
No. Another symptom caused by hemochromatosis that one would get from drinking excessive blood would also be dehydration.
Due to the high iron content mentioned earlier, and your body’s struggle to expel it, drinking blood would have a negative hydration factor, and as such would leave you thirstier than you originally was.
So, if you were lost in the desert with nothing to drink could you drink your own blood? Yes.
Should you? No.
Will it hydrate you? Absolutely not.
What should you do? Lie down in the sun, get a tan, and hope for rescue.