The textbook summarizes the results of emotional and body stress research conducted by the author over the years. Changes in emotions and behavior of different people with brief and prolonged stress were analyzed. From the standpoint of pathopsychology, alexithymia ("wordlessness of feelings") and the phenomenon of "splitting emotions" are considered. "Engine storm" and "imaginary death" were studied in battles in the North Caucasus. The results of the author's fundamental studies of the "motion sickness" syndrome and methods for its prevention are presented. Particular attention is paid to how psychological stressors affect the vegetative sphere (physiological systems) of the body. Methods and techniques for maintaining health and performance under stress are shown.