Rheumatoid factor (RF)

Rheumatoid factor (RF) is a protein (antibody) made by the immune system that can attack the body's own tissues. An elevated rheumatoid factor may indicate the presence of an inflammatory disease.

Rheumatoid factor can be measured with a blood test. This is most helpful for diagnosing rheumatoid arthritis, lupus, and Sjögren's syndrome. Certain heart and liver diseases, infectious diseases (such as tuberculosis), and normal aging may also increase RF levels.

Last Updated: June 25, 2008

Author: Shannon Erstad, MBA/MPH

Medical Review: Michael J. Sexton, MD - Pediatrics & Stanford M. Shoor, MD - Rheumatology

related physicians

related services

Bon Secours International| Sisters of Bon Secours USA| Bon Secours Health System

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995-2010 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.