Teenagers are the most vulnerable subjects for the onset of Anorexia Nervosa (AN), in the period they start facing important body changes as well as a new status of authonomy and independence. AN is considered a severe health problem with mental and physical consequences that may be life- threatening. When a teenager is suffering from an eating disorder his/her parents are suffering too, feeling powerless, frustrated and preoccupied. So they also need help. The special focus of this book is on Anorexia Nervosa in adolescence. The book is divided in three parts. A first general part with the description of what AN is and how it may interfere with the natural growth and development during adolescence, a second part in which psychopathological signs and symptoms as well as neuropsychological features of AN are presented and finally a third part dealing with the assessment and the treatment. In this last part different evidence-based approaches are presented and discussed, with a particular emphasis on the model used by the Eating Disorder Unit in Padova, Italy. This book is addressed to therapists, healthcare workers, primary care physicians and mental care trainees and to all those who can get in touch with people at risk to develop or still suffering from anorexia nervosa, but, as it is written in a very easy and direct style, it can be addressed to patients, parents, teachers and coaches as well. It may be a tool to improve the detection of warning signs and symptoms of AN for early diagnosis, a tool to better understand what AN can mean to young affected people, and it can also be a useful guide in clinical practice.