I had a very important conversation with my cousin today. She recently discovered a close friend of hers uses cutting as a coping mechanism. She was alarmed, as most people would be. And her friend was ashamed, as most people would be. I'd like to offer a different point of view.
As mentioned before*, we like to think of ourselves as in charge; that our conscious mind is the decision maker. This is far from true. Our conscious mind is more like the rider on an elephant (the subconscious). Sure, we can direct it some, but it's mostly in charge. And when it goes wild, we have little control over our actions.
Cutting is not something to be ashamed of, in my opinion. It's a symptom of a larger issue and should be corrected if possible, but it's not a shameful act. It's a very powerful act of a person desperately trying to bring themselves in charge of their life again. Causing physical pain to oneself is a way to force the body and brain to go into a healing process. I can even tell you the biology.
Serotonin, that feel good chemical, is also the chemical used by the body to do wound healing (along with a host of other chemicals). Serotonin acts as a vasoconstrictor, that is, it makes the blood vessels shrink. This helps in two ways: it slows the loss of blood from the body and it closes access to the smallest blood vessels in the skin so that bacteria can't get in. As a side effect, it also is hugely calming.
The pain of the wound has to match the emotional pain inside. That's normal. What someone is doing is raising the serotonin level physically to be able to block out the emotional pain. That's nothing to be ashamed of. That was actually the scientific theory behind the Occipital Nerve Stimulator: if you can give the nerves enough stimulation (yes, it was painful) it can block the start and formation of the migraine.
When people are cutting, they are intuitively self-healing. That's nothing to be ashamed of. But it does scare people.
We don't need to be afraid of cutting. But it might be a good idea to find a way to create the same healing process in a constructive way. I frequently would use clothe spins when my hands were particularly achey. That pain and pressure of the clothes pins would allow me to relax my hands and stop the cycle for a while.
Similarly, I find that the pressure of water can be very soothing. This is actual science too, as discovered by Temple Grandin. Pressure in the body, like a hug or a bath, has a calming effect. Based on this science they now have hugging machines to help people with conditions like Autisim.
Cutting is something to be concerned about (for health reasons), but cutting is something that is intuitively natural. It's not something to be afraid of.
If you want to help yourself or someone else, I would suggest exploring other avenues to get that same stimulation without causing bodily harm. Be very careful. Look for ways that are safe.
I will admit, I'm a fan of a technique called mummification. I use Vet Wrap, designed for sprained ankles. It's a self sticking bandage that causes slight compression when used correctly. Wrapping this around my whole body is the most relaxing sensation I have ever felt. I was able to reach a wonderful meditative state where I could look at any issue I had calmly and without fear or dread. I'll borrow the quote from the Order of the Garter: Honi soit qui mal y pense (Old French: "shame upon him who thinks evil upon it", or "evil to him who evil thinks").
Life is rough and frequently overwhelming. It's okay that we have limits. We're allowed to take care of ourselves in safe and constructive ways, unusual though they may be. The point is we're trying to manage our elephant as best we can. We're trying to get through hell. Life is like that sometimes, and that's nothing to be ashamed of. It happens to everyone, no exception.
The key to walking through hell is: Don't stop.
*There is a TED talk that mentions this Elephant/Rider theory: Stefan Sagmeister: 7 rules for making more happiness. Go to time marker 3:30 if you want to skip ahead.