Most of them self harm because the removal the pain feels good - and it takes with it some emotional pain.
Though there probably are some masochists that truly enjoy the pain, but that's a different condition than the more common I-hate-myself-so-I-hurt-myself.
Not quite. The pain causes an endorphin release. It's also addictive (not technically by the DSM sense, but those who do will often call it as such) and has been compared to heroin.
Though there probably are some masochists that truly enjoy the pain, but that's a different condition than the more common I-hate-myself-so-I-hurt-myself.