Autosadism — also called automasochism — is the practice of putting pain or humiliation on yourself. In a kink frame it is the moment the sadist and the masochist occupy the same body: the person who wants the hurt is also the person who delivers it. The word covers a range from a paraphilia built around sexual arousal to acts that sit next to ordinary self-harm, and the distinction matters. One is an erotic script. The other is injury without that charge. They can look alike from the outside.
Masochism, sublimated sadism, and algolagnia
Writers have treated autosadism as a form of masochism, as a sublimated form of sadism, or as a route into algolagnia — the sexual tendency defined by taking pleasure and stimulation from physical pain. The masochist reading is the obvious one: you want the sting, so you supply it. The sublimated-sadism reading is colder. The wish to hurt is turned inward; the target is still a body, but it is your own. Algolagnia names the sensory payoff without forcing a top/bottom split. Pain itself is the charge, whether a partner or your own hand produces it. That is the whole useful map. Same-person sadism is not a third orientation so much as a way the usual pair of roles collapses into one pair of hands.
