Blood Loss

            Law of Hemoglobin Capacity– The human body contains over 12 gallons of blood, sometimes more, under high pressure. (Darrin Bright and Ryan Shellito)


Ah yes the classic anime trope of giant rivers of blood gushing out of the body to signify a grievous injury that doesn’t actually manage to slow anyone down, unless it’s needed for dramatic effect.  Also, this particular trope is not in any way limited to anime, as Hollywood and other media outlets love to use it as well.


The law of hemoglobin capacity can be broken down into two parts.

1- The human body contains over 12 gallons of blood

2- The blood is kept at high pressure and has a tendency to explode from the body at high speed when the body is cut.


Real World Biology

            The human body actually contains around 5 liters of blood, depending on the size of the person in question.  This accounts for about 8% of the individual’s body weight.  To give you an idea, the total amount of blood in the body is equal to this:


The next item to consider about blood is the ability of a character to lose nearly all of it and still manage to continue doing whatever it was they were doing, as seen here.

In this case our poor heroine was rather excited and lost a considerable amount of blood through a nosebleed (something I will address at a later date).  So much blood that it is doing a rather good job of painting the walls red.  Sadly, this would be a rather bad thing if it were to occur in the real world.



Shock is a condition where the body is shutting down due to the immense amount of stress being put on it, and there are a variety of types depending on the cause of the shock.  Today we will be talking about circulatory shock.  This occurs when an individual is losing a lot of due to an injury or illness, although injury is far more common, specifically called hypovolemic shock.  Hypovolemic shock can be broken down into several categories based on the amount of blood that is lost.


Class Amount of blood lost Bodies response Outcome
1 <15% (0.75L) Increased HR Fine
2 15-30% (0.75-1.5L) Increased HR+ decreased BP Probably fine with treatment
3 30-40% (1.5-2L) All of the above+ Confusion+ clammy skin+ shallow breathing+ weakness+ pallor Survivable with immediate treatment
4 >40% (2L+) All of the above plus loss of consciousness Potential of death even with aggressive treatment


As for our previous example, given the amount of blood that is staining the walls, she should be in class 3 shock.  Thus, there is no way she is standing there red-faced, rather she should be lying on the ground pale-faced, and confused.  As such we can call the first part of the law of hemoglobin capacity busted.

Find more anime science at


SOURCEAnime Science
Chris Meharg
Just your average science teacher, and anime fan. I've been watching anime since I was a wee little kid, but didn't really get into anime until college. I enjoy talking an analytical look at anime to see just how well it portrays science. So let me know if you've got an anime you'd like to see me take a look at. Currently having fun teaching overseas.
Loading Disqus Comments ...
Loading Facebook Comments ...


Please enter your comment!
Please enter your name here