This article analyzes diagnosis as a literary and institutional practice of classification, focusing on Maylis de Kerangal’s Mend the Living and Han Kang’s The Vegetarian. Grounded in Georges Canguilhem’s theory of the normal and the pathological, it suggests that our bodily states are meaningful not simply through measurement, but rather by the norms, values and classificatory systems that establish what forms of life can be known, cured, deployed or excluded. In Mend the Living, Simon Limbeau is both the corpse and a source of transferrable organs, hijacked by transplant medicine to create the hybrid of dead subject and viable organ. Kerangal’s procedural, and yet lyrical, narration reveals the moral dilemma of biomedical functionality versus individual uniqueness. In contrast, Han employs a disjointed form of narration which defies any attempt at diagnostic closure, exposing the violence of normalisation. The narrator of The Vegetarian understands Yeong-hye’s refusal of meat, food and sexuality–her rejection of the human legible–as pathological to be addressed by husband, family, and psychiatry. At a deeper level, this article demonstrates that diagnosis does not just receive an explicit medical thematization. It is formally enacted through acts of narration, focalization, bodily description, and institutional procedure. By reframing approaches to indexicality from illness representation to diagnosis as a kind of classification poetics, the study contributes to medical humanities