Autoimmune / Rheumatology
Also known as: RF Blood Test
If you experience sudden severe joint pain, swelling, redness, or fever, contact your clinician immediately. No common urgent flag from this test alone.
The Rheumatoid Factor (RF) test checks for a protein in your blood. This protein is called rheumatoid factor. Your body's defense system sometimes makes this protein by mistake. It attacks your healthy cells instead of fighting off germs.
Your doctor orders this test to help find out if you have certain health problems. These include rheumatoid arthritis, Sjögren's syndrome, and other diseases where your body attacks itself. It can also help check for infections or cancer. This is especially true if you have symptoms like joint pain or stiffness.
Reference ranges for rheumatoid factor can vary between different laboratories. Your results will often be reported as positive or negative, or as a specific amount with a normal range provided by the testing lab.
Clinical Reference
175932200080307Medicare covers for therapeutic drug monitoring
Educational purposes only — This information is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your lab results with your healthcare provider.