Rheumatoid factor is rheumatoid factor, routine blood test can not check rheumatoid factor, the test does not include rheumatoid factor. Routine blood tests mainly include white blood cell count, red blood cell count, platelet count, hematocrit and leukocyte count, etc., which does not include rheumatoid factor, rheumatoid factor generally belongs to the immune-related tests in the rheumatism of one of the three, in addition to this also includes anti-“O” and C-reactive protein or sedimentation. Rheumatoid factor is important for the diagnosis of rheumatoid arthritis and efficacy, typing, rheumatoid factor titer and rheumatoid arthritis patients with a positive correlation between the clinical performance, in addition to this, rheumatoid factor is also dry syndrome, systemic lupus erythematosus, scleroderma, and other autoimmune diseases have a certain clinical significance. It is recommended that patients who need to test rheumatoid factor go to the rheumatology and immunology department of regular hospitals for detailed consultation.