Patients with rheumatic arthritis generally do not have elevated rheumatoid factor levels, but there may also be a slight, minor increase. Typically, high titers of positive rheumatoid factors are not present. If a patient with rheumatic arthritis has a significant increase in rheumatoid factor, that is, more than three times the normal value, we need to reconsider the diagnosis of rheumatic arthritis. At this point, further tests are required to refine the diagnosis, including ASO (anti-streptolysin O), ESR (erythrocyte sedimentation rate), CRP (C-reactive protein), anti-CCP antibody, and anti-AK antibody, to better determine whether the condition is rheumatic arthritis or rheumatoid arthritis.