The cause of rheumatoid arthritis is unknown, and there may not be one specific cause. In about 75 per cent of patients, it begins gradually, with only mild symptoms at first. These may include malaise, fever, weight loss, and morning joint stiffness.
Some bodily bone connections may become swollen, painful, and inflamed and most patients have increasingly severe and many attacks with subsequent joint damage and deformity with rheumatoid arthritis.
Besides the joint changes, rheumatoid arthritis may include atrophy of muscles, bones, and the skin adjacent to the affected bone structure or structures between the bones. The most evident lesions are subcutaneous nodules, usually over bony areas that are less protected; such as, the elbows.