Self-harm is not a mental illness, but a behavior that indicates a lack of coping skills. Several illnesses are associated with it, including borderline personality disorder, depression, eating disorders, anxiety or posttraumatic distress disorder.
Self-harm occurs most often during the teenage and young adult years, though it can also happen later in life. Those at the most risk are people who have experienced trauma, neglect or abuse. For instance, if a person grew up in an unstable family, it might have become a coping mechanism. If a person binge drinks or does drugs, he is also at greater risk of self-injury, because alcohol and drugs lower self-control.
The urge to hurt yourself may start with overwhelming anger, frustration or pain. When a person is not sure how to deal with emotions, or learned as a child to hide emotions, self-harm may feel like a release. Sometimes, injuring yourself stimulates the body’s endorphins or pain-killing hormones, thus raising their mood. Or if a person doesn’t feel many emotions, he might cause himself pain in order to feel something “real” to replace emotional numbness.