The DSM-5 proposes that self-harm be recognized as a diagnostic category of mental disease, compared to its previous definition as a behavioral symptom. Based on fieldwork in London, I challenge this proposal by exploring the life-history of a homeless sex-worker and substance-user who practices self-cutting. By bringing phenomenological anthropology into conversation with psychoanalytic theory, this article provisionally re-conceptualizes self-harm as an ethics of self-reparation and existential affirmation in the face of extreme precarity. Approached as an agentive practice through which human beings reclaim "somethingness" by altering their bodily conditions, we can conceive self-harm in a way that is attentive to the situational conditions that shape existential pain, instead of reaching straight for the diagnostic toolkit. In taking self-harm as simultaneously a reaction to and a reflection on existential crisis-rather than a sui generis disorder-this paper situates such practices as a pluralized condition-of-world rather than a bounded pathology-of-mind.