Lupus is an autoimmune disease. It inflames:

  • Joints
  • Tendons
  • Skin
  • Other connective tissue and organs

It causes the immune system to make antibodies that attack the body's healthy cells and tissue.

The cause of lupus is unknown. Researchers believe it may be a combination of:

  • Genetic factors
  • Environmental factors, which may include:
    • Sunlight (UV rays)
    • Stress
  • Viral or other type of infection
  • Drug-induced (methyldopa, procainamide, hydralazine, isoniazid, chlorpromazine, TNF-blocking drugs)