Self-harm is the act of harming oneself. There are many ways that one may execute such an action, such as: Burns, cuts, and banging certain parts of the body to make bruises. It is somewhat similar to suicidal thoughts, as the person in question may be considering such a thing. Self-harm can be a symptom of depression or bipolar disorder. This is a very serious warning sign where help may be needed. The body tends to slow down, possibly to keep oneself from harming themselves.