Rheumatoid factor is an immune system protein. Doctors can measure its levels using a blood test to help diagnose autoimmune conditions, including rheumatoid arthritis. Here, we explain the test, normal rheumatoid factor ranges, and what the results mean.
Medical News Today: Rheumatoid factor: What to know
Rheumatoid factor is an immune system protein. Doctors can measure its levels using a blood test to help diagnose autoimmune conditions, including rheumatoid arthritis. Here, we explain the test, normal rheumatoid factor ranges, and what the results mean.