I don't know if I could call it wrong. It's not common at least. I think most people would consider consumption of human blood cannibalism, though as long as it's consensual and doesn't result in significant harm I wouldn't call it a wrong practice.
No, it's not wrong to crave the taste of blood. It's actually a common recipe in other countries for native dishes. But be warned, the human stomach isn't meant to handle digestion of blood and so drinking or consuming blood can build up in the bottom of your stomach and cause blockages known as bezoar's, Which in the long run can kill you..
I think it's pretty common to crave the 'taste of blood' or be at least intrigued by it. It's not wrong as long as no one gets harmed and you don't have excessive amounts (kinda need yours to live and others for blood transfusions and that sweatdrop).
Consuming your own blood is fine, if one day you cut yourself too deep or do something wrong, you'll probably die and that would be your own problem.
Consuming someone else's blood is a problem (if it's not consensual, that is).
But.. who am I to judge? I'm Transylvanian..
I believe it's considered self-cannibalism, but it's fairly common. Most people don't fess up to it.
I suffer from Dermatillomania, a skin picking disorder. Part of this is eating the skin you pick off. Not everyone who picks their skin does it, but most do. I do. It's disgusting and I hate it, but it's something I am not in control of at all.
I mean, as long as you aren't biting off chunks of your own flesh, I don't think it's too much of a problem. I know my disorder signals that my wiring is weird or I'm missing a few screws, but I am not compulsed to go eat other people.
I do like biting, though.
As with all harmful habits, the answer is "yes," regardless of the reason. As it stands I don't think it's the end of the world, but there are definite health concerns here, the potential of scarring only one of them