Chapter 4 offers a comprehensive introduction to ethical questions raised in the context of health, disease, and well-being. Under the rubric of ‘health care ethics’, we address a wide range of topics including the patient-physician relationship, the role of AI in healthcare, the ethics of reproductive health, the fair allocation of public health resources, the ethics of health promotion and prevention, and the ethics of biomedical research. The chapter opens with an introduction to bioethics’ most-used toolkit: the principles of biomedical ethics. It offers an overview of these principles and explains how they relate to the moral theories discussed in previous chapters. Before delving into specific applications, the chapter presents important critiques that highlight the complexity of ethical theorizing and decision-making, and remind us of the need to involve a wide variety of perspectives, with particular attention to stakeholders. Throughout the chapter, the reader will learn how to apply these insights in a nuanced and context-sensitive way by working through a variety of ethical topics in the context of healthcare, public health, and clinical research.