The exact cause of rheumatoid arthritis is not known. Rheumatoid arthritis is an autoimmune disorder, which means the body's immune system attacks its own healthy cells and tissues. The response of the body causes inflammation in and around the joints, which then may lead to a destruction of the skeletal system.
Rheumatoid arthritis also may have devastating effects to other organs, such as the heart and lungs. Researchers believe certain factors, including heredity, may contribute to the onset of the disease.