The normal reference range for Rheumatoid Factor is 0~20IU/mL, and the test found that Rheumatoid Factor 30.4IU/mL is higher than the upper limit of the normal reference range, which is abnormal. Rheumatoid factor is a kind of autoantibody, the normal reference range is 0~20IU/mL, so 30.4IU/mL is higher than the upper limit of its normal reference range, which is a positive result. Rheumatoid factor test is mainly used for the diagnosis of rheumatoid arthritis, and its positivity can also be seen in systemic lupus erythematosus, chronic active hepatitis, scleroderma, and some of the elderly and other conditions. Therefore, patients with a rheumatoid factor test result of 30.4 IU/mL should further communicate with their physicians in detail and improve the blood sedimentation, CRP, X-ray, ultrasound, autoantibodies and other related auxiliary tests to clarify the causes of rheumatoid factor abnormalities. Laboratory test results should be interpreted by a professional physician, it is recommended that patients with rheumatoid factor of 30.4IU/mL should go to the rheumatology and immunology department of a regular hospital for further consultation.