Autoimmune disease

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The immune system is the body's defense against foreign substances, such as bacteria or viruses, that may be harmful. An autoimmune disease is an abnormal condition that occurs when a person's immune system attacks its own tissues as though they were foreign substances.

  • Normally, when a foreign substance enters the body, the immune system creates special proteins (antibodies) and white blood cells to attack and destroy the foreign substance.
  • In a person with an autoimmune disease, the immune system recognizes some of the person's own tissues as foreign substances. The body makes antibodies and other cells that attack and destroy these tissues. This process often leads to inflammation and eventually, if it continues, scarring and destruction of the organs that are made up of those tissues.

Why the body attacks its own cells is not known. Autoimmune diseases include lupus, rheumatoid arthritis, scleroderma, and Sjögren's syndrome. Certain types of diabetes and thyroid disease are related to autoimmune reactions. Some autoimmune diseases can cause a higher risk for infections.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.