Rheumatoid arthritis is characterised by chronic polyarthritis – meaning that it affects many joints. In about two thirds of patients it begins insidiously with fatigue, and vague muscle and joint symptoms until the appearance of the synovial inflammation is apparent. This may persist for weeks or months.
Specific symptoms usually appear gradually as several joints, particularly those of the hands, wrists, knees and feet become affected on both sides of the body.
About 10% of people have a more atypical presentation with sudden onset of polyarthritis, sometimes together with fever and a systemic illness, or with a single joint such as a knee involved.
The main symptoms are stiffness, pain and tenderness in all inflamed joints. Generalised stiffness is common and usually worse after inactivity. There is usually morning stiffness lasting more than one hour. The duration of morning stiffness can be used as a crude measure of the degree of inflammation, as it improves with treatment.
Inflammation of the synovium causes swelling, tenderness and limitation of motion. The joint may be warm to the touch, particularly the large joints.
Joint swelling results from accumulation of fluid within the synovial space, thickening of the synovium and thickening of the joint capsule. The inflamed joint maybe held in a partly flexed position since this minimises pain. Later, fixed deformities of the joints arise as a result of joint damage.
There are also many non-joint manifestations of rheumatoid arthritis.
Causes of rheumatoid arthritis
Diagnosing rheumatoid arthritis
Reviewed by Dr Dr I C Louw, Rheumatologist/Physician and Dr A Halland, Rheumatologist/Physician, March 2007