Rheumatoid arthritis is a chronic inflammatory disorder that most typically affects the small joints in the hands and feet. Unlike the wear-and-tear damage of osteoarthritis, rheumatoid arthritis affects the lining of the joints ('synovium'), causing a painful swelling that can eventually result in bone erosion and joint deformity.
An autoimmune disorder, rheumatoid arthritis occurs when the immune system mistakenly attacks itself instead of foreign invaders like bacteria. In addition to causing joint problems, rheumatoid arthritis can affect the whole body with fevers and fatigue.
Rheumatoid arthritis is two to three times more common in women than in men and generally occurs between the ages of 40 and 60. While there's no cure for rheumatoid arthritis, treatment options have expanded greatly in the past few decades.
More information can be found at 'Rheumatoid Arthritis in the Foot'.