Self-injury is any intentional act that causes harm to one’s own body for the purpose of emotional relief. Self-injury can involve a variety of behaviors, including cutting, burning, scratching, biting, pinching, hitting, head-banging and hair-pulling. Tattoos and body piercings are not typically considered self-injury.

The majority of self-injurers are young women. Significant factors that increase a person's risk of self-injury are a history of physical or sexual abuse and an inability to express negative emotions such as anger or sadness. Self-injury can also be a symptom of a number of different mental disorders including major depression, bipolar disorder, borderline personality disorder (BPD), bulimia nervosa and substance abuse.

It is often difficult to determine that self-injury is occurring. Self-injurers often hurt themselves in private and conceal or make excuses for any resulting scars, burns or bruises. Intense feelings of shame often prevent them from discussing their behavior with others. However, there are signs to look for, including wounds that do not heal, bald spots and frequent injuries at various stages of healing.

Self-injury requires immediate professional attention. Suspected self-injurers should receive a mental health evaluation in which they will be asked to discuss their history of previous self-injury, as well as the function of and thoughts behind the self-injury. A physical examination may also be necessary, with emphasis on any areas of the body where self-injury has occurred. 

Treatment for self-injury may include medication for any underlying mental disorders, cognitive behavior therapy (CBT), interpersonal therapy (IPT) or other types of psychotherapy.