This reference presents over 5000 definitions and descriptions of medical terms and concepts. These are accompanied by appendices on subjects such as the National Health Service (including selected statistics), health economics, complementary and alternative medicine, common medical tests and an address list of support and professional organizations. All the material has been checked for this edition and updated, with revised material on topics such as apoptosis, autism, cognitive behaviour therapy, environmental health, ethics, nursing, occupational health, prostheses, suicide, and transfusion.