Rheumatoid Factor

Rheumatoid Factor (RF) is a protein produced by the immune system that can indicate an autoimmune disorder, particularly rheumatoid arthritis. In this condition, the body mistakenly attacks its own tissues, leading to joint inflammation and damage. While RF is often present in people with rheumatoid arthritis, it can also appear in other diseases and some healthy individuals. Doctors test for RF through a blood sample to help diagnose or monitor these conditions, but it is just one piece of the puzzle and must be considered alongside other tests and symptoms.