Rheumatoid arthritis is when the body's defence system against disease accidentally attacks itself and causes the joint lining to swell. It can affect joints in any part of the body but mostly affects the hands, wrists and knees. In more severe cases, it can affect other areas like the skin, eyes and nerves. Signs of rheumatoid arthritis include joints being swollen, warm, painful and stiff, most commonly in the early morning after sleeping or after long periods of inactivity.
Attribution: Straight Talk Foundation