Rheumatoid arthritis is a chronic disease that causes inflammation in the joints and certain other organs throughout the body. It is called an autoimmune disorder. It is believed that the body’s immune system accidentally mistakes its own tissues for foreign invaders. The immune system attacks the joints and organs, causing damage.

Rheumatoid Arthritis
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Researchers are not sure what causes the immune system to respond so destructively. It may be caused by a combination of factors, including:

  • Genes—People with rheumatoid arthritis may have a specific genetic defect that increases their risk for developing this condition.
  • Defects in the immune system may cause the immune cells to fail to recognize the body’s own tissues.
  • Infection with specific viruses or bacteria that kick off an abnormal immune response. However, so far no infection has been found.
  • Chemical or hormonal imbalances in the body.

More than 1.5 million Americans (about 1% of the adult population) have rheumatoid arthritis.