German neurophysiologist and popularizer of science Peter Sporck discusses issues relevant to many categories of the population. The life of a modern person is full of stress, which often results in sleep disturbances. Almost all psychiatric patients and many people suffering from somatic disorders have sleep problems. The author, in an accessible and clear manner, talks about the physiological mechanisms of sleep, various manifestations of sleep disorders, sleep in animals, sleep learning, and offers a number of tests to identify and correct some disorders of this function. The book provides the latest scientific data and is equipped with a bibliography. The book will be of interest to somnologists and medical practitioners, as well as to everyone interested in this topic.