If you are being really serious here, it is a clinical problem. It can be related to OCD (Obsessive Compulsive Disorder) or it could be an attention seeking behavior. It also could be someone in a phase of mania, or even schizophrenia. Anyways it is a serious problem some people have, I have seen people cut themselves BIGTIME, saying they are "cutting out the demons" etc.... can get really deep in psychology!
"I don't want to know emptiness, take me down to the water wanna be baptized in your love far away from the lonliness, take my heart and wash away the fear let me be baptized in your love"