This book provides a state of the art review on the care and treatment of and current scientific knowledge on gender dysphoria (GD) and disorders of sex development (DSD). The book elucidates the history, the present situation, and the newest developments and future perspectives in both research on GD and DSD and the clinical management of individuals with GD and DSD of all ages. With contributions from a selection of leading scientists and established clinicians in the field of GD and DSD, this is a unique and comprehensive book focusing on the etiology and developmental trajectories of GD and DSD regarding gender identity development, psychiatric comorbidity, classification dilemmas, ethical dilemmas in treatment, influences of societal stigmatization, and discussion of the medical and psychological implications and outcomes of treatment, and providing treatment guidelines for individuals with GD and DSD (distinct guidelines each for children, adolescents, and adults). By presenting not only an historic overview and the current state of the art, but also challenges for the future, the book aims to demonstrate the need for further research and to stimulate the development and improvement of the clinical care of individuals with GD and DSD.