Autocannibalism
Autocannibalism, also known as self-cannibalism and autosarcophagy, is the practice of eating parts of one's own body. Generally, only the consumption of flesh by an individual of the same species is considered cannibalism. In line with this usage, self-cannibalism means the consumption of flesh from one's own body. While some texts use this strict definition, others use the term autocannibalism in a wider sense that includes the consumption of hair or nails from one's own body.
Both humans and some animal species occasionally practice self-cannibalism. In humans, it can be a symptom of a mental disorder, but there are also a handful of people who have voluntarily consumed an amputated body part. In other cases, people were forced to eat parts of themselves as a form of torture.
A similar term that is applied differently is autophagy, which specifically denotes the normal process of self-degradation by cells. While typically used only for this specific process, autophagy has nonetheless occasionally been used as a general synonym for self-cannibalism.
Humans
As a disorder or symptom thereof
Fingernail-biting that develops into fingernail-eating is a form of pica. Other forms of pica include dermatophagia and trichophagia. The latter can lead to hairballs in one's stomach. If untreated, this can cause death due to excessive hair buildup.Self-cannibalism can be a form of self-harm and a symptom of a mental disorder. Some also consider it a mental disorder in its own right, but it is not listed in the widely used DSM-5.
As a choice
Some people will engage in self-cannibalism as an extreme form of body modification, for example, by ingesting parts of their own skin. In very rare cases, people have eaten a part of their own body that had to be amputated for medical reasons; such acts may be motivated by curiosity or a desire to attract attention. It has been argued that such cases are ethically acceptable because the resultant meat was taken from a person who is still alive and who gave consent for their flesh to be eaten.Some people drink their own blood, a practice called autovampirism, but sucking blood from wounds is generally not considered cannibalism.
As a crime
Forced self-cannibalism as a form of torture or war crime has been reported. Elizabeth Báthory allegedly forced some of her servants to eat their own flesh in the early 17th century. During the violence that followed the 1991 Haitian coup d'état, victims sometimes had to eat their own hacked-off body parts. In the 1990s, young people in Uganda were forced to eat their own ears.Related practices
Eating one's own placenta has a small following in Western cultures, fostered by celebrities like January Jones. Human placentophagy after childbirth is touted by some as a treatment for postpartum depression and fatigue, among other health benefits, given its high protein, rich iron and nutrient content. However, scientific research is inconclusive as to whether consuming the placenta has any health benefits, exceeding that of readily acquired meats.While the status of placentophagy as cannibalism is debated, Harriet Hall has pointed out that "placental tissue is mainly derived from the fertilized egg and carries the fetus's genome", suggesting that the placenta is a temporary organ of the fetus rather than of the mother. Therefore, even if one considers placentophagy a form of cannibalism, a mother eating her baby's placenta after giving birth would not practice self-cannibalism.