In recent decades, and due to the publication of works from authors such as Jacques Derrida and Giorgio Agamben, the classical question about the relationship between the human and the animal has been reactivated and rethought in the philosophical world. In particular, Friedrich Nietzsche's philosophy provides one of the most interesting example in which the relationship between human existence and animality has been described, providing us with an extremely original and productive way of dealing with this relationship. The present work aims the following objectives: 1) In the first place, the contribution contextualizes and examines the scope and consequences of the Nietzschean definition of man as "the sick animal" ("das kranke Tier"), 2) to interpret both the medical-biological as well as the metaphorical meaning of health and disease as agonistic expressions, in order to 3) assess the uniqueness of man's "sickness". Finally, the study asks and evaluates 4) to what extent this approach effectively represents an advance for the anthropological questions.