Anorexia nervosa is an eating disorder characterized by extreme food restriction and an intense fear of gaining weight. The signs and symptoms of anorexia nervosa can be classified into emotional, physical, and behavioral aspects. Some emotional and behavioral symptoms are social withdrawal, insomnia, irritability, and frequent checks in the mirror for perceived flaws. Thin appearance, abnormal blood counts, fatigue, dehydration and swelling in the body are some common physical symptoms of anorexia nervosa. The diagnosis of this condition includes physical examination by a doctor followed by some tests. Blood tests, urine tests, electrocardiogram, thyroid function tests, imaging tests such as computed tomography (CT) scan, and bone density scan are commonly used to diagnose anorexia nervosa. The treatment for anorexia is aimed at overcoming both psychological and physical symptoms. It includes medications, counseling, and therapies. This book outlines the diagnosis and treatment for anorexia nervosa in detail. It will serve as a valuable source of reference for graduate and post graduate students.