Self-cannibalism

Self-cannibalism is the practice of eating oneself, also called autocannibalism, or autosarcophagy. A similar term which is applied differently is autophagy, which specifically denotes the normal process of self-degradation by cells. While almost an exclusive term for this process, autophagy nonetheless has occasionally made its way into more common usage.

Among humans

As a natural occurrence

A certain amount of self-cannibalism occurs unwittingly, as the body consumes dead cells from the tongue and cheeks. Ingesting one's own blood from an unintentional lesion such as a nose-bleed or an ulcer is clearly not intentional harvesting and consequently not considered cannibalistic.

Catabolisis is also sometimes described as "self-cannibalism."

As a disorder or symptom thereof

Fingernail-biting that develops into fingernail-eating is a form of pica, although many do not consider nail biting as a true form of cannibalism. Other forms of pica include the compulsion of eating one's own hair, which can form a hairball in the stomach.