This review (Part II of a series on sleep disorders) presents an update of the characteristics, epidemiology, assessment, and latest management of insomnia, restless legs syndrome (Willis-Ekbom disease; RLS/WED), and narcolepsy. Insomnia, the most common sleep disorder and most prevalent of all psychological health disorders, is a problem of difficulty initiating and maintaining sleep and early morning awakenings. RLS/WED is characterized by a crawling sensation or urge to move the legs in the evening and nighttime. Narcolepsy is a sleep disorder that commonly results in chronic daytime sleepiness and cataplexy. Nonpharmacological management, which includes education, cognitive behavioral therapy, and complementary therapy, is used as primary or adjunctive to pharmacotherapy for the treatment of these disorders.This narrative review utilized medical databases such as PubMed to identify relevant English-language original and systematic review articles predominantly from peer-reviewed journals from 2012 to 2019. However, as background, findings from classic articles prior to 2012 were also included.Assessment of sleep problems, excessive sleepiness, and difficulty performing activities or being productive should be routine in the care of all patients. Utilization of behavioral interventions, including cognitive behavioral therapy, in addition to education and sleep hygiene, can promote sleep quality. Management of insomnia, RLS/WED, and narcolepsy should include helping patients adjust to treatment, managing cataplexy triggers in narcolepsy, and initiating strategies to live with chronic illness to improve quality of life.