The saddest problem I see is self mutalization

Self harm can be a form of cathartic release, emotional expression (when you feel like you are unable to express your negative emotions any other way), and of punishment. Sometimes when you are in a place where you want to self harm, you feel so maddeningly numb and apathetic, you almost start to feel inhuman, hurting yourself and seeing yourself bleed is like a break from that, for a little while you feel real and human again.
Self harm is often an expression of deep self loathing.
Cutting or hurting yourself also causes a chemical reaction in your brain that helps you feel better for a short while, which can make it very addictive for some people.

People's reasons for self harming vary greatly.

Cutters cut because they are overwhelmed with emotions, often to the point of numbness. Inflicting minor physical pain enables them to feel something and have it be under their control. Rarely dangerous, cutting is typically superficial. Once in a while, it goes farther by accident.
This behavior is often seen in young women and those with certain personality disorders and/or histories of abuse.

Maybe I can shed some light on this.

Our physiology is complex.

Are you familiar with "runner's high"? The brain responds to the pain a long distance runner endures by dumping endorphins, which helps the runner endure the pain but also creates that odd feeling we call runner's high. In BDSM, this is referred to most often as "subspace".

A good top, the one in charge of the actions, can read his bottom and modulate the sensations between pain and pleasure such that the bottom cannot distinguish between the two. A sadist does not love giving pain to make people feel bad. He gives pain to make people feel good. And, there are plenty of women that top, also.

I've seen some interesting pics of artistic cuttings, but they are hard to find. Even fetish sites ban them over legal concerns. I can honestly say, it's not my kink, but some people get into it.

I (we) don't care if YOU understand. It's none of your business and you could instead consider yourself fortunate you've never had those feelings.

To get away from emotional pain, intense anger or frustration. It stops bad feelings and sort of gives you control because it is something you have complete control over.

yes it is to relieve mental and emotional pain. there were lots on ep who cut themselves.

I dont do it but had a nephew that did. The physical pain takes away the deep emotional pain.