is a chronic, autoimmune disease
. It is an inflammatory type of arthritis
which affects the joints
. The disease also may have systemic effects, affecting other organs of the body. Symptoms of rheumatoid arthritis include joint pain
, joint stiffness, joint inflammation
and joint deformity
. Fever, malaise, severe fatigue
, and morning stiffness
lasting more than one hour are also common symptoms associated with rheumatoid arthritis.
About 80 percent of rheumatoid arthritis patients test positive for rheumatoid factor (detected by a blood test). Approximately 20 percent of rheumatoid arthritis patients are classified as having "seronegative rheumatoid arthritis" because they lack rheumatoid factor.
With rheumatoid arthritis, there is a symmetrical pattern of affected joints. For example, both knees of a patient are usually affected rather than one knee.