Juvenile chronic arthritis (JHA) and rheumatoid arthritis (RA) of adults diseases close to the mechanisms of their development The tendency to chronic course, frequent disability due to disorders of the musculoskeletal system and a relatively high incidence of damage to internal organs make these diseases very significant in social terms. Until now, a number of rheumatologists have expressed doubts about the nosological unity of the Yukha and RA. However, it should be emphasized that the difference between juvenile and adult forms of rheumatoid arthritis is purely quantitative, but not qualitative. In children, all clinical manifestations of RA that occur in adults are described, and you can see quite similar variants of the course and outcome of the disease. Similarly, it can be argued that for adult patients, descriptions are given of such forms that are characteristic of the symptoms and course of early YHA .. Similar parallels can be given by the constellations of immunological characteristics of the disease .. This textbook in no way aims to replace students with relevant educational and monographic literature , Although a number of sections, Related to Individual Therapeutic Tactics , Clinical Trials , Prevention , It is described in more detail in .. It also seems to us that the preparation of such a publication jointly by pediatricians and therapists in its methodological basis will allow students who study these diseases in 3-6 courses to better imagine the importance of continuity in the management of patients with these chronic diseases. Finally, the manual includes some materials on UHA and RA obtained at the departments of faculty therapy and propaedeutics of children's diseases of LPMI, which makes it possible for students to get acquainted with the scientific direction of these departments. Although this tutorial is intended primarily for students, however, it can, to some extent, be useful for teachers.