Causes
It's generally believed that lupus is caused by alterations in the immune
system. The body's immune
system normally fights foreign bacteria and viruses; however, with lupus, the
immune system may fail to recognize "self" substances and will make
antibodies that attack the body's own tissue. This is called autoimmunity. The body may also fail to clear
antigens (foreign particles), and certain white blood cells may behave
abnormally.
The exact cause of lupus is still unknown. However, it is recognized that
sunlight causes symptoms to flare up. Other triggers include viral infections,
stress, and certain medications.