Nobody knows what causes lupus, the most likely explanation lies in the complex interplay between genetic, hormonal and environmental factors but we still don't understand how these factors come together to cause the body's immune system to function in such a dysfunctional way.
The NHS site says that the following appear to act as triggers in some people:
It is believed that there is a genetic predisposition to the disease as lupus runs in families, although only 10% of lupus patients will have a parent or sibling who already has, or may, develop the condition. The Lupus Foundation of America reports recent discoveries which indicate a gene on chromosome 1 which is associated with lupus in certain families.
It is thought that hormonal factors may account for the fact that nine times as many women are affected as men but we don't fully understand the reasons for this. Some research has shown an increased risk of lupus with high levels of oestrogen but this has been contradicted in other tests.
Wikipaedia puts forward the notion that the autoimmune response may be caused by the body's failure to clear up dead cells.
Smoking may increase the risk of getting lupus and may make the disease more severe.
