The rise of the term global health reflects a concern with rethinking the meaning of health in the context of globalization. As a field of practice, however, global health renders problems, populations, and spaces visible and amenable to intervention in differentiated ways. Whereas some problems are considered to be global, others are not. Some are considered to be matters of global security, whereas others lack this designation and remain in the realm of health or development. Attention is drawn to individual global health problems, even as their broader structural dimensions are often obscured. We suggest that a critical geographical approach to global health therefore entails reflexivity about the processes by which problems are constituted and addressed as issues of global health and identify three analytical approaches that offer complementary insights into them: governmentality, risk, and assemblage. We conclude by outlining some further issues for critically reflexive geographies of global health.