Negative rheumatoid factor means that it may be a normal condition, but rheumatoid arthritis, systemic lupus erythematosus and other diseases cannot be excluded. Rheumatoid factor is due to bacteria, viruses and other pathogens infected with the human body to denatured lgG as the antigen of the antibody, normal people also exist in the body of a small amount of rheumatoid factor, rheumatoid factor positive is mainly suggestive of rheumatoid arthritis, dermatomyositis, and other autoimmune diseases, but the rheumatoid factor negative can not be excluded from this type of disease. Negative rheumatoid factor may be normal, but it can also be seen in serology negative rheumatoid arthritis, therefore, if patients with negative rheumatoid factor have joint pain, rash and other discomforts, they need to further improve the blood sedimentation, CRP, autoantibodies, X-rays and other auxiliary tests to further clarify the cause of the disease. It is recommended that patients with rheumatoid factor-negative rheumatoid arthritis but with symptoms such as joint pain and rash should go to the rheumatology department of a regular hospital for detailed consultation.