Rheumatoid arthritis (RA) is an autoimmune disease that causes swelling, pain, and stiffness in the joints. It can also increase your risk of osteoporosis, making bones fragile and prone to fractures.

Rheumatoid factor (RF) is a type of antibody, an immune system protein that helps the body fight foreign substances like bacteria and viruses, called antigens. Antibodies, also known as ...

September 7, 2012 — Elevated rheumatoid factor (RF) levels in healthy patients may be a strong predictor of future rheumatoid arthritis (RA), according to data from a prospective cohort study ...

When persistent joint pain strikes, the search for answers often leads to a crucial diagnostic tool: the rheumatoid factor test. This relatively quick blood analysis serves as a window into the immune ...