A rheumatologist is an internist or pediatrician who received further training in the diagnosis (detection) and treatment of musculoskeletal disease and systemic autoimmune conditions commonly referred to as rheumatic diseases. The medical field that studies these types of conditions is called rheumatology. Rheumatology is a subspecialty in internal medicine and pediatrics that deals with the joints, soft tissues, autoimmune diseases and heritable. Rheumatology is a branch of medicine devoted to the diagnosis and therapy of rheumatic diseases. Rheumatology is a branch of medicine devoted to the diagnosis and therapy of rheumatic diseases. Rheumatoid arthritis is a chronic inflammatory disorder that can affect more than just your joints.