the pain keeps, what is going on in their head, away. <br />
it's the only thing they concentrate on in that moment and they feel release from all their problems and thoughts.
when someone is in huge amounts of emotional pain, they deal with it sometimes irrationally, but it's the nature of the suffering to sometimes take it out on ourselves instead of responding face to face with the hurt.
depends, sometimes with some people, they've had something traumatic happen to them and it has left them emotionally numb, cutting themselves to feel pain is the only sense of pain they get.
-.- It's a coping strategy. You can only understand once you've been in that position