It depends.
Bloodletting, as in real, or even simulated, cutting one's self or another person is prohibited by our camsite rules. I don't know that self injury is actually illegal however you might be committed to a psychiatric hospital involuntarily though ...
There is lots of blood faked in mainstream movies so it's obviously not illegal in that context.
United States v. Extreme Associates, Inc - Wikipedia, the free encyclopedia.
They did federal prison time.
But that was not blood but rather rape and sadistic simulated violence.
https://www.google.com/search?num=50...etting+in+porn
I'll let google take the wrap
caution: q=bloodletting+in+porn