Why do people self-harm/cut themselves?

I used to. It was punishing myself and/or distracting emotional pain with physical pain. You get addicted, too. It releases endorphins

its easier to deal with physical pain rather than emotional pain

For me, the physical pain made me feel human again. I used to feel so numb. Like, when your leg falls asleep and you can feel the pressure of your hand on your skin... but you don't really feel it. That's how my emotions were, that's what my whole life was. I felt dead, inhuman, and isolated, and like I was screaming with no voice. The sharp physical pain of cutting sort of stopped stopped that for a bit and I felt a little better in a way for a short time.
It was also a form of punishment. A manifestation of my intense self loathing.
It was a coping method.

It brings a physical feeling to my mental pain. I can feel a cut stop hurting. I can see a cut heal.

I used it for attention and punishment

I've heard it feels like a release.

I only cut myself once, and I agree, it just causes pain. At the time I did it because I thought I deserved it. There's really no rational reason why a person should cut themselves, but you're not really thinking rationally when you're that depressed.

I don't think it's something I will ever understand despite how much I've read about it. It was a very uncommon phenomenon in the air I grew up with, but cutting seems to be all the rage these days.

This post should come with a trigger warning for people who do self harm

As a distraction from emotional pain or self punishment too.

Yeah, I don't know either. Doing so has never crossed my mind.

if i bleed ,i must be real .