Book excerpt: This concise text takes a symptom-based approach to evaluate and treat sleep disorders. Divided into two sections, this book emphasizes practical information in the patient history and physical, the latest screening techniques and common sleep disorders that either cause sleepiness, insomnia, or restless sleep. Chapters cover the epidemiology, pathophysiology, diagnosis and treatment of major sleep disorders and incorporate new classification systems from the International Classifications of Sleep Disorders, 3rd Edition and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Sleepy or Sleepless provides a solid foundation to clinicians who want to better evaluate patients with sleep-related complaints.