How Do I know If I Have Arthritis?
In addition to symptoms and a doctor's exam, blood tests and X-rays are commonly used to confirm rheumatoid arthritis. The majority of sufferers have antibodies called rheumatoid factors (RF) in their blood, although RF may also be present in other disorders. A new test for rheumatoid arthritis that measures levels of antibodies in the blood (called the anti-CCP test) is more specific and tends to be only elevated in patients with rheumatoid arthritis or in patients about to develop rheumatoid arthritis. The presence of anti-CCP antibodies can also be used to predict which patients will get more severe rheumatoid arthritis.
X-rays are used to diagnose osteoarthritis, typically revealing a loss of cartilage and joint destruction. Sometimes blood tests and joint aspiration (using a needle to draw a small sample of fluid from the joint for testing) are used to rule out other types of arthritis. If your doctor suspects infectious arthritis as a complication of some other disease, testing a sample of fluid from the affected joint will usually confirm the diagnosis.