Unlike other forms of arthritis, rheumatoid arthritis is a systemic autoimmune disease that is not caused by common wear-and-tear on the joint. This condition usually affects joints symmetrically (for example, both knees, both wrists, both shoulders). Rheumatoid arthritis causes degeneration of the articular or joint cartilage. It can also affect the tissue that surrounds and lubricates the joint. If the joint surfaces and cartilage are not lubricated they can start to rub, causing wear.
Rheumatoid arthritis can affect other parts of the body including organs like the heart and lungs, and can even cause fatigue. The cause of Rheumatoid arthritis is not fully known. It is considered an autoimmune disease, where the cells of the body attack themselves. Although it is a chronic condition, individuals can have periods of little to no symptoms mixed with acute or symptomatic periods. There can be a genetic component to this disease.