Over the last few years there has been a substantial increase in the interest not only by the medical profession but also the media in the role of testosterone in health and disease. This interest has been mirrored by a rapid increase in research publications and development of improved modes of delivery of testosterone therapy. This new pocketbook provides a comprehensive but concise and up-to-date knowledge of established and salient new data on the management of testosterone deficiency. It includes a background of essential knowledge on the diagnosis, treatment and safety. It also explores the associations of testosterone deficiency with organ systems and their diseases such as diabetes and osteoporosis.