At least 1 in 600 adults wound themselves sufficiently to need hospital treatment. More men than women do it, although more women receive psychological treatment. Many have a history of sexual or physical abuse. Self-wounding differs from other self-harm in being aimed neither at mutilation nor at death. Self-wounding coerces others and relieves personal distress. Repeated self-wounding is one criterion of borderline personality disorder but we prefer to consider it an 'addictive' behaviour rather than an expression of a wider disorder. Psychological management may need to be augmented by drug or social treatment. Carers, including professional carers, usually need help to contain the turbulence that self-wounding produces.