Rheumatoid Factor

About This Test
Rheumatoid Factor (RF) is an autoantibody that can target your own antibodies. High RF is common in rheumatoid arthritis but can also appear in other autoimmune conditions and some infections, so results are always read with symptoms and other tests (e.g., anti-CCP, ESR/CRP). RF helps doctors understand if joint pain and stiffness may be inflammatory in nature. This test is commonly included in arthritis work-ups to support early diagnosis and treatment planning.

Patient Preparation
No fasting needed

Best Time to Test
Anytime

Tests Included
Rheumatoid Factor

Why is it done
Evaluation of persistent joint pain, morning stiffness, or swollen small joints; supporting the diagnosis of rheumatoid arthritis together with anti-CCP and exam findings; baseline prognosis (higher titers may correlate with more active disease); distinguishing autoimmune causes from non-inflammatory joint problems; occasional elevation in conditions like Sjögren’s or chronic infections is considered in interpretation.