Focused on the intersection of health, drug use, and poverty, this dissertation closely examines the use of discursive registers in the conceptualization of health among low-income people who inject drugs in New York City. Using qualitative in-depth interviews with 40 people who inject drugs, 13 health care practitioners who provide care for drug-using patients, and 4 researchers of drug use, the governmentality of a public health risk population--people who inject drugs--is traced. To historicize this population a genealogy of the injection drug user is conducted through the examination of public health research publications from the 1980s and historical literature on the HIV/AIDS epidemic. This dissertation sought to answer such questions as: How did the emergence in the 1980s of the injection drug user function as an act of governmentality? How do health care practitioners understand drug use among their patients and what are the implications of these understandings for the management of their health and their selves? How have risk discourse and particularly harm reduction discourse produced concepts of health and governed the bodies of low-income people who inject drugs? And, what can be done about health concerns that fall outside of risk discourse? The findings of this dissertation interrogate discourses of risk, such as harm reduction, and the discourse of addiction as disease by pointing to the narratives of illness offered by people who inject drugs. These narratives reveal that these individuals prioritize chronic health conditions from which they currently suffer over concerns of risk for infectious disease or the disease of addiction. Despite this, people who inject drugs are entangled in a complicated web of power through bio-political discourses of risk and disease that renders them subjects of disciplinary and pastoral technologies of power