This article explores the links between health, security and politics, with the objective of providing the groundwork for a political analysis of health in the discipline of International Relations. It makes two arguments. Firstly, it argues that health can be seen as form of politics; secondly, it suggests that security provides a good lens to analyse the political work of health. The article makes the case for seeing health as more than a medical condition and/or a set of technical solutions. Rather, health should be approached as a set of perceptions, understandings and practices that mobilize forms of power and are constitutive of social relations and the political realm. The article shows that the health-security nexus, and particularly its two articulations securitization of health and medicalization of security, constitutes a good indicator of how health is constitutive of politics at the international level.