Rheumatoid Arthritis Diagnosis

Diagnosing rheumatoid arthritis can be very challenging, as its symptoms often mimic those of other diseases, and the onset of symptoms can be gradual. Obtaining an accurate diagnosis typically requires a series of testing, such as blood tests, imaging scans, and a physical examination with thorough medical history.

Blood Tests

One of the markers detectable by blood is the presence of rheumatoid factor, which is an antibody found in the blood. Approximately 80% of rheumatoid arthritis patients show an elevated level of rheumatoid factor; however, detection of high levels does not confirm a diagnosis of rheumatoid arthritis. An elevated level of rheumatoid factor found in conjunction with pain in the same joints on both sides of the body is a strong indicator for rheumatoid arthritis.

Another type of blood test used to help diagnose rheumatoid arthritis is the erythrocyte sedimentation rate test (ESR). The faster red blood cells (erythrocytes) fall to the bottom of a tube filled with the patient’s blood, the greater the degree of inflammation. Because inflammation is a factor in many conditions, this test is not specific for rheumatoid arthritis and by itself does not diagnose a patient, but can suggest the diagnosis. It is also used to see how active the condition is.

A third test is the anti-CCP antibody test. The presence of antibodies directed against cyclic citrulinated peptides (CCP) can identify rheumatoid arthritis long before symptoms ever develop. When used in combination with the test for rheumatoid factor, this is the best predictor of patients who will develop more severe rheumatoid arthritis.

Imaging Techniques

X-Ray. While x-rays can be helpful in detecting bone damage (erosions) that occurs as a result of rheumatoid arthritis, they are not often used as a diagnostic tool because early damage to the soft tissue cannot be detected.

Extremity MRI. Special magnetic resonance imaging techniques, termed extremity MRI, can be used to detect bone damage in the hands of rheumatoid arthritis patients when x-rays have not proven helpful. Further evaluation is necessary to determine the usefulness of MRI as a regularly employed diagnostic tool as MRI tests can be very expensive.

Ultrasound. Ultrasound is a newer technique used to see erosions from rheumatoid arthritis at an early stage. It is not used routinely.

Physical Examination and Medical History

The appointment will likely begin with the physician taking a thorough medical history. This will include asking the patient to describe his or her symptoms, such as:

• Where the symptoms are
• Description of the pain (such as dull and aching or sharp, constant or intermittent)
• When the symptoms began
• How they have changed over time
• What makes the patient feel better or worse (certain activities)

The history will also include a review of any other medical problems, previous treatments, and medications. Because there is also a genetic component to the disease, the physician will also ask about medical problems of close family members.

The physical examination will evaluate the patient’s general health and then a physician will evaluate all the joints for involvement.