As of 2015, the cause of lupus is still unknown, according to the Lupus Foundation of America. However, scientists theorize that exposure to certain environmental factors, having a genetic disposition to the disease, and the body's own hormones may trigger the disease.
Lupus is an autoimmune disease in which the body's immune system attacks healthy tissue, according to WebMD. The flare-ups can start as a result of a person's genetic disposition to the disease, as it shows a tendency to develop within families, explains the Lupus Foundation of America. Also, certain genes, while not outright causing the disease, are considered potential contributors.
In these people with genetic dispositions to the disease, scientists theorize that exposure to an outside factor, such as a specific type of virus or a certain chemical, triggers the disease, notes the Lupus Foundation of America. Other potential triggers include ultraviolet light, injury, undergoing severe stress and certain antibiotic drugs.
Finally, a person's hormones may trigger the disease, states the Lupus Foundation of America. Nine out of 10 cases of lupus occur in women, which caused researchers to look into the links between estrogen production and lupus. What they discovered is that women tend to have more severe cases of lupus before menstruation and during pregnancy, when estrogen production is high. While this suggests the severity of the disease is regulated by estrogen production, no causal effect has been proven.