The objective of this book is to promote and enable closer co-operation between different health professionals in treating pain, by introducing psychosocially oriented team members to the medical aspects of pain, and medically oriented team members to the psychosocial aspects. The structure of the book completely mirrors this objective. The book has nine parts, arranged according to a balanced plan. Parts I and II deal with theoretical (basic science) approaches to pain, whereby Part I focuses on the medical approaches and Part II on the psychosocial ones. Part III is devoted to pain evaluation and assessment, whereby chapter 9 deals with the medical aspects, chapter 10 with the psychophysiological and psychiatric aspects, and chapter 11 with the psychological psychometric approach, describing different commonly used questionnaires for assessing various aspects of pain. Parts IV to Part VII are devoted to treatment of pain. Part IV focuses on medical treatments, Part V on psychological treatments, Part VI on palliative approaches, and Part VII on complementary approaches (mainly those supported by enough research and evidence). Part VIII focuses on particular pain syndromes, those that are most frequent in the practice of pain, emphasising both medical and psychological aspects in each chapter. Finally, Part IX deals with the practice of treating pain -- in chapter 29 with the facilities and pain centres, namely, the locations where the integration of the described approaches to pain is expected to take place, and in chapter 30 with the problems of the health professional that treats pain.