German neurophysiologist and science popularizer Peter Spork discusses issues relevant to many categories of the population. The life of a modern person is full of stress, which often causes sleep disturbances. Almost all patients of psychiatrists and many people suffering from somatic disorders have problems with sleep. The author talks in an accessible and clear form about the physiological mechanisms of sleep, various manifestations of sleep disorders, sleep in animals, learning in sleep and offers a number of tests to identify and correct some of the disorders of this function. The book contains the latest scientific data, it is equipped with a bibliography. Will arouse interest among researchers-somnologists and practitioners, as well as everyone interested in this topic.