The manual is intended to study the most important and relevant aspects of the work of a family doctor. Particular attention is paid to the presentation of issues of organizing the activities of a doctor and carrying out preventive measures within the framework of family medicine. The book reveals the specifics of semiotics, diagnosis of the main conditions encountered in a doctor’s practice. The information presented is intended to facilitate the acquisition of skills in the differential diagnosis of diseases of internal organs, the acquisition of knowledge about the modern arsenal of diagnostic methods, will help a specialist assess symptoms and syndromes, correctly formulate a diagnosis, determine a list of differentiated diseases, and plan the nature of the therapy. The content and volume of the manual correspond to the curriculum for medical universities and faculties for training doctors in the “Family Medicine” section.