This paper proposes a phenomenological understanding of alexithymia. The disturbance -- an inability to express feelings -- is presented, and conceptual problems concerning the diagnosis and theories of its etiology are discussed. In a survey of the clinical literature, explanatory theories suggested in the fields of neurophysiology and psychoanalysis are scrutinized. Three territories that fail to relate to each other in a proper way in the alexithymic personality type -- language, feeling, and body -- are by these means identified. In order to reach a coherent understanding of alexithymia, a phenomenological interpretation is developed with the aid of the philosophy of Martin Heidegger. The hermeneutics of "being-in-the-world" that Heidegger outlines in his first important work, Sein und Zeit, is utilized to find a connection between body, feeling, and language as meaning-structuring phenomena. The "worldliness" of the alexithymic person is understood as a defective form of attunement, similar to what Heidegger develops as das Man. The analysis of this form of being-in-the-world makes it possible to understand alexithymia as a defective meaning structure that embraces the social communion of language as well as the living body of...