This chapter introduces the central concepts underpinning the right to health. Firstly, it describes the genesis of the international right to health, starting with the Constitution of the World Health Organization (WHO). Secondly, it introduces key elements of states ’ legal obligations for the right to health, as developed by the UN Committee on Economic, Social and Cultural Rights. Thirdly, it discusses how the right to health embraces a broad range of issues, including the determinants of health, and the Sustainable Development Goals. Fourthly, it introduces controversies associated with the right to health, including matters such as interpretation, justiciability and responsibility for the realization of the right.