In the decade since AIDS was first recognised the enormous and worldwide social and medical implications of this disease have been increasingly recognised. The exponential increase in the number of people infected with HIV has been paralleled by the written literature on the subject. When this book was initially conceived the question was why another book? It seemed to me at that time and since, that as HIV presented ever more complex problems, they were best solved when considered within a wider context, using basic principles of individual medical specialties and applying them. For this reason, all the chapter authors were experienced in a particular field and applied that knowledge to HIV. All the authors were working at the Middlesex Hospital in London when the AIDS services there were expanding to fill a need, from 2 beds in 1986 to two wards today. The authors were frontline staff looking after all aspects of HIV infection within a wider general medical context. Many are now consultants or senior lecturers. It is the aim of the book to provide an insight into HIV and AIDS as a overview for someone starting to work in this field or who sees such patients occasionally and requires some basic guidelines. For this reason the chapters are based predominantly on organ systems and are divided into sections covering the presenta­ tion, methods of investigation and treatment or action required of relevant conditions.