The manual contains up-to-date data on the role of stress, heredity, constitution, age of a person in the development of diseases, as well as basic information on such structural, metabolic and functional changes of a destructive nature as pathology of tissue growth, allergies, metabolic disorders, heart and respiratory failure. Mechanisms of protective reactions of organism are considered. It tells about teratology, offers quite detailed information about the causes and mechanisms of the development of congenital malformations, chromosomal diseases and gene syndromes.