[Rheumatoid arthritis--general concepts]

It is most important to recognize that Rheumatoid Arthritis (RA) is a multiple organ disease, and not a disease restricted only to the joint and muscle. RA is one of the collagen diseases or connective tissues diseases, and the pathogenesis is still not clear but an autoimmune phenomenon should be related with the genesis of the disease and a genetic background might be correlated. In this paper, the general concepts on RA are described from (1) the position of RA in collagen disease, connective tissue disease, autoimmune disease or auto-allergic disease and rheumatic disease, (2) recognition of pathophysiological and clinical figure of RA as a whole body disorder, (3) the procedures for diagnosis in various types of RA and (4) considerations of the treatment.