Rheumatoid factor 200IU/mL may be due to rheumatoid arthritis, systemic lupus erythematosus and other diseases, leading to rheumatoid factor elevation of different diseases, the harm produced by the corresponding differences, may lead to bone destruction, joint deformity, disability, generalized edema and other hazards to the patient. The normal reference range of rheumatoid factor is 0~20IU/mL, so the patient’s rheumatoid factor test result of 200IU/mL has far exceeded the upper limit of the normal reference range, which is mostly seen in rheumatoid arthritis, desiccation syndrome, dermatomyositis, systemic lupus erythematosus, and other autoimmune diseases, but only by the rheumatoid factor can’t be directly defined by the patient’s diagnosis. Different diseases causing abnormal elevation of rheumatoid factor may cause different hazards to patients, for example, untreated rheumatoid arthritis may lead to joint deformity or disability, while systemic lupus erythematosus may involve multiple organs and systems and lead to lupus nephritis, antiphospholipid syndrome, intestinal necrosis and other complications, which in severe cases may lead to the death of the patient and other hazards. Rheumatoid factor test results should be interpreted by a professional physician, it is recommended that patients with a rheumatoid factor of 200IU/mL go to the rheumatology and immunology department of a regular hospital for detailed consultation.