Rheumatoid Factor (RF)-Reference Range

Rheumatoid factor is an antibody that is detectable in the blood of approximately 80% of adults with rheumatoid arthritis.

The normal range for rheumatoid factor is less than 14 IU/ml. Any result with values 14 IU/ml or above is considered abnormally high, elevated, or positive.

High levels of rheumatoid factor may indicate:

  • Rheumatoid arthritis (RA)
  • Rheumatoid nodules
  • Rheumatoid lung disease

It should be noticed that a negative RF test does not rule out RA. About 20% of people with RA will have very low levels of or no detectable RF.

Keywords: Rheumatoid Factor (RF)

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.