The book is devoted to selenomedicine - a direction of science that studies the influence of the moon on human life. The extensive material of modern literature shows the importance of changing the lunar phases and tidal phenomena in the functioning of the human body in normal and pathological conditions. The role of the Moon and tides as synchronizers of biorhythms is considered. The results of studies of the influence of the moon obtained in different fields of medicine, as well as in psychology, forensics, etc. are analyzed and compared in detail. Possible mechanisms of the influence of the Moon on humans are described. The book is designed for doctors, biometeorologists, chronobiologists.