What is Rheumatoid Arthritis (RA)?
RA is a chronic inflammatory disease. Although it principally affects joints, it may also adversely affect many other bodily systems. In RA, many joints are usually affected simultaneously (RA is a Polyarthritis). Small joints are typically affected first, with onward progression to involve larger joints. Joints tend to be affected in a symmetrical manner (i.e. both hands, both feet).
The basic abnormality is an inflammation of the joint lining (the synovium). The inflamed lining multiplies and grows out over the surface of the joint, destroying cartilage and underlying bone. This damage can be identified on X-ray and is known as ‘erosions’. Eventually this process leads to joint destruction.
Affected joints become painful, stiff, swollen and can become deformed.
RA affects the entire body, not just the joints. The disease is able to involve a multitude of bodily systems or target organs (Figure 1 below). Fatigue is a common feature and there may also be fever and weight loss, especially during periods of active inflammation (flare-ups).
In addition to the inflammatory effects of RA, due to pain and disuse of joints, there may be muscle wasting and dramatic changes in lifestyle.
Due to joint destruction, secondary Osteo-arthritis (OA) often develops in joints affected by RA.
Figure 2 below lists the principal differences between RA and OA.
The effects of disability in severe RA are generally worse than those experienced in OA. There is no cure for RA, but with modern treatment the effects of the disease have been reduced with fewer joint deformities and disability. After 10 years from diagnosis, 10% will have severe disability, whilst 25% will have minimal if any symptoms at all. The remainder will fall between these two extremes.
Figure 1 - Bodily Systems that may be adversely affected by RA
- Nose and ear
- Nervous system
Figure 2 - Principal differences between OA and RA
|Not inflammatory (cartilage destruction and new bone formation)||Inflammatory (inflammation of joint lining – synovium)|
|General health unaffected||Reduced general health and fatigue|
|Variable joint involvement (but tends to affect hip and knees)||Small joints affected first (i.e. wrists, fingers and toes)|
|May affect function in a few joints only||Many joints functionally affected (Polyarthritis)|