Medical Critical Theory introduces an interdisciplinary framework for understanding how illness experience and social suffering intersect in late modern societies. Drawing on critical theory, medical phenomenology, phenomenological psychopathology, and social epidemiology, Domonkos Sik examines how structural distortions shape mental health and physical illness, and how these insights can inform emancipatory praxis. The book argues that contemporary critical theory has lost touch with pressing social pathologies, while phenomenological approaches remain overly individualistic. It bridges these gaps by synthesizing phenomenological accounts of illness with Frankfurt School traditions, offering a grounded and practical concept of social pathology informed by phenomenological perspectives on lived experience. Through detailed case studies of psychosis, depression, asthma, hypertension, and lung cancer, the book demonstrates how hostile, instrumentalizing, and disruptive intersubjectivities affect health outcomes. It also proposes practical strategies for mental health activism and social change, including medico-social forms of solidarity, illness communities, and a reworked Stoic ethic to counter activist fatigue. This volume will appeal to scholars and researchers in critical theory, philosophy, medical humanities, medical sociology, and disability studies, as well as those interested in the phenomenology of illness, mental health policy, and the politics of medicalization.