A rheumatologist is a medical professional who diagnoses and treats patients who have rheumatic diseases, such as arthritis and osteoarthritis. Rheumatologists specialize in rheumatology, which is the study of diseases and disorders that affect the joints, ligaments and muscles.
In addition to managing chronic diseases, rheumatologists also work to treat individuals with musculoskeletal problems related to a particular region of the body, such as knee, shoulder and hip pain. To become rheumatologists, after completing medical school, individuals participate in a residency program, then two to three years specifically training in rheumatology before taking a national exam. As of 2015, approximately 20,000 patients a year see a rheumatologist, according to the Mayo Clinic.