Blood testing:
Blood tests help with the diagnosis of RA, as well as to monitor the progression of the disease. These may include:

• Erythrocyte sedimentation rate (ESR)
  A measure of the rate at which red blood cells settle in a tube of blood during one hour. The ESR is a measure of inflammation and it increases in RA.
• C-reactive protein (CRP)
  C-reactive protein is released by the liver into the blood during an inflammatory condition. A high value indicates inflammation (from infection or inflammatory diseases such as autoimmune diseases including RA).
• Rheumatoid Factor (RF)
  RF is an autoantibody identified by a blood test. A positive RF result in addition to the typical clinical findings is presumptive of RA.
• Anti-CCP
  Assay for the detection of auto-antibodies which are highly specific for RA; anti-CCP is used for the diagnosis of (early) disease and to differentiate RA patients from patients with other rheumatic diseases. Several studies indicate that the presence of anti-CCP may predate symptoms and may predict a more severe course of disease.

Radiological imaging
Plain film radiography is the standard investigation to assess the extent of anatomic changes in RA patients. The radiographic features of the hand joints in early disease are characterized by soft tissue swelling and mild juxtaarticular osteoporosis. Erosions of bone are not usually visible for several months after the onset of the disease, except through the use of specialised techniques such as microfocal X-ray.

In the past ten years, ultrasonography has gained acceptance for studying joint, tendon and bursal involvement in RA. It may improve the early clinical assessment and the follow-up of patients, showing details such as synovial thickening even within finger joints. Other imaging techniques, such as magnetic resonance, computed tomography and scintigraphy may provide useful information about both the features and the extent of anatomic damage in selected RA patients.