The formation of identity and subjectivity in relation to health is a fundamental issue in social science. This overview distinguishes two different approaches to the workings of power in shaping senses of self and other. Politics of identity scholars focus on social movements and organizations concerned with discrimination, recognition, and social justice. The biopower approach examines discourse and technology as they influence subjectivity and new forms of sociality. Recent work in medical anthropology, especially on chronic problems, illustrates the two approaches and also points to the significance of detailed comparative ethnography for problematizing them. By analyzing the political and economic bases of health, and by embedding health conditions in the other concerns of daily life, comparative ethnography ensures differentiation and nuance. It helps us to grasp the uneven effects of social conditions on the possibilities for the formation of health identities and subjectivities.