Hello, Rheumatoid factor (RF) is a blood test that measures the amount of the RF antibody in the blood. Most patients with rheumatoid arthritis, and almost all patients with Sjogren syndrome have positive RF tests. However, not everyone with higher levels of rheumatoid factor has rheumatoid arthritis or Sjogren syndrome. People with the following diseases may also have higher levels of rheumatoid factor: Scleroderma Systemic lupus erythematosus Dermatomyositis Sarcoidosis Higher-than-normal levels of RF may be seen in people with other medical problems. However, these higher RF levels cannot be used to diagnose these other conditions.: AIDS, hepatitis, influenza,  and other viral infections Certain kidney diseases Endocarditis, tuberculosis, and other bacterial infections Parasite infections Leukemia, multiple myeloma, and other cancers etc Sometimes, people who are healthy and have no other medical problem will have a higher-than-normal RF level. Since you don t have persistent pain and swelling in your joints and anti CCP antibodies etc are negative,other causes should be looked into. Thanks