It means different things to different people. For some it is a way to let out feelings that you have found no other outlet for, or it can be a way to communicate, to tell someone that you need help (in my opinion, even if you try to hide it or deny it), or a way to control your feelings - to feel something when all you are feeling is numb, or to dull the intense pain that you are in emotionally. There are many other meanings - probably as many as there are self-injurers. Or more, since the meaning can change from one time to another.

<font color=orange>"Success is the ability to go from failure to failure without losing your enthusiasm. - Winston Churchill "</font color=orange>