Rheumatoid arthritis is a common chronic, systemic autoimmune disease that often involves the joints of the hands, wrists, shoulders and elbows, knees, ankles, temporomandibular joints, and neck. Inflammation often causes destruction of joint bone, cartilage, and synovial membranes, ultimately leading to joint deformity and loss of function. Current laboratory tests can assist clinicians in early diagnosis of rheumatoid arthritis, and early treatment can reduce joint damage and prevent joint deformity and loss of function.