[Sleep disorders and what underlies them]

This paper will have 3 purposes: --To describe some new concepts about how the physiology of normal sleep provides the substrates for sleep pathology. --To outline new approaches to daytime sleepiness as the key result of nocturnal sleep disturbance. --To outline the gamut of currently known sleep pathologies. The author concludes that somnology, clinical specialty of sleep disorders will lead the way in devising and testing specific treatment and in establishing rational indications for providing symptomatic relief with sedative/hypnotics. It seems likely that polysomnographic diagnosis will become much more widespread and that G.P.'s will want to refer their patients to a sleep disorders center to obtain evaluation and treatment recommendations.