Some self injure because it's the only way that they feel in control of something. By hurting themselves, they are in control of something that happens to them. It's the only way that they can feel in control. Self injury is a way that some people deal with feelings. It doesn't mean that they want to die, but they need a release.
Friends can help by understanding and being there.
They're afraid of getting caught, but in the same light, sometimes they do. All of these thoughts are my own and someone who is qualified to help someone with this disorder obviously knows a lot more. Visit the sites below for more info.