The second half of the twentieth century witnessed the emergence of a new model of chronic disease-diagnosed on the basis of numerical deviations rather than symptoms and treated on a preventive basis before any overt signs of illness develop-that arose in concert with a set of safe, effective, and highly marketable prescription drugs. In Prescribing by Numbers, physician-historian Jeremy A. Greene examines the mechanisms by which drugs and chronic disease categories define one another within medical research, clinical practice, and pharmaceutical marketing, and he explores how this interaction has profoundly altered the experience, politics, ethics, and economy of health in late-twentieth-century America. Prescribing by Numbers highlights the complex historical role of pharmaceuticals in the transformation of disease categories. Greene narrates the expanding definition of the three principal cardiovascular risk factors-hypertension, diabetes, and high cholesterol-each intersecting with the career of a particular pharmaceutical agent. Drawing on documents from corporate archives and contemporary pharmaceutical marketing literature in concert with the clinical literature and the records of researchers, clinicians, and public health advocates, Greene produces a fascinating account of the expansion of the pharmaceutical treatment of chronic disease over the past fifty years. While acknowledging the influence of pharmaceutical marketing on physicians, Greene avoids demonizing drug companies. Rather, his provocative and comprehensive analysis sheds light on the increasing presence of the subjectively healthy but highly medicated individual in the American medical landscape, suggesting how historical analysis can help to address the problems inherent in the program of pharmaceutical prevention.