Lupus is thought to develop when your body's immune system mistakenly attacks the body's own tissues. . Immune proteins called autoantibodies attack many different parts of the body, causing inflammation and tissue damage in many parts of the body, including the joints, skin, kidney, nervous system (brain, spinal cord and nerves), blood, heart, lungs, digestive system and eyes. Autoantibodies also can attach themselves to body chemicals, forming abnormal molecules called immune complexes that trigger additional inflammation and injury when they are deposited in various organs and tissues.
The exact cause of lupus remains a mystery, although scientists are investigating many different possibilities and believe several factors may play a role in the development of the disease. Since 90% of all lupus patients are women, usually of childbearing age, researchers think hormones may be involved. Lupus tends to run in families, so genetic factors may play a role. There is some evidence that the illness may be more common in people of African, Native American, West Indian and Chinese descent. Some researchers think lupus may be triggered by a virus or another type of infection in people who are genetically susceptible to the disease.
Lupus is relatively rare, affecting less than one in 2,000 people. The scientific name of the disease is systemic lupus erythematosus, or SLE.