An extremely rare and under-researched condition, Body Integrity Identity Disorder (BIID) alters a person’s self-perception and results in a desire to amputate certain body parts or sever the spinal cord. Commonly, the limb or body part is perfectly healthy and in working order, but sufferers feel a disconnect between how they feel their body should look and their actual body composition. [source: PubMed]
Though shocking, mismatches between someone's body perception and their actual body are not uncommon. Those who have suffered an accidental amputation often report feelings of a phantom limb. [source: University of Oxford]
In a 2011 study, researchers at the University of Amsterdam found that out of the 54 BIID subjects studied, the main reasoning for amputation was to “feel complete or feel satisfied inside.” Amputation of one or more limbs was preferred by 55.6%, and 44.4% wished to be disabled or paralyzed. [source: Plos One]
Some subjects also reported a sexual arousal when imagining amputation or seeing an amputee. [source: Plos One] Many respondents described a discord with where their limbs end and where they feel they should end. Commonly causing extreme distress, those diagnosed with BIID may turn to surgery to modify their limbs.
Though not much research has been done on the cause of this disorder, treatments exist primarily in the form of medication. Similar medications used for Obsessive Compulsive Disorder are thought to help minimize the anxious desire for amputation in BIID patients.[source: BIID.org]