[Sleep apnea].

Regular and unobstructed breathing during the night is the prerequisite for an undisturbed and restful sleep. The most prevalent nocturnal breathing disturbance with morbid consequences is the obstructive sleep apnea syndrome. Forms severe enough to need therapy and, therefore, a thorough work-up, can be usually detected by a detailed history. Pathophysiology, clinical findings, differential diagnosis as well as work-up and therapy of the sleep apnea syndrome are discussed.