Knowledge and understanding of issues relating to fitness, health and disease are important parts of A level biology but also lead to better informed choices now and in the future. This text explains the meaning of good health and describes the causes of infections and other diseases. It also looks at the diagnosis and treatment of genetic conditions and some of the ethical dilemmas that arise. Case studies are provided. Questions at the end of each chapter are designed to be used for data analysis, to test understanding and for discussion and debate. A glossary of key terms is included.