No one knows what causes lupus. Scientists think that people are born with the genes to develop lupus and that something brings on or "triggers" the disease and symptoms. However, a combination of genetics (heredity), environment, and hormones is involved. Learn more about the factors that may cause of lupus .
No gene or group of genes has been proven to cause lupus. Lupus does, however, appear in certain families, and when one of two identical twins has lupus, there is an increased chance that the other twin will also develop the disease. These findings, as well as others, strongly suggest that genes are involved in the development of lupus.
While a person’s genes may increase the chance that he or she will develop lupus, it takes some kind of environmental trigger to set off the illness or to bring on a flare. Examples may include
a cold or a viral illness
emotional stress, such as a divorce, illness, death in the family, or other life complications
anything that causes stress to the body, such as surgery, physical harm, pregnancy, or giving birth
In particular, the sex hormone estrogen plays a role in lupus. Men and women both produce estrogen, but estrogen production is much greater in females. Many women have more lupus symptoms before menstrual periods and/or during pregnancy, when estrogen production is high. This may indicate that estrogen somehow regulates the severity of lupus. However, it does not mean that estrogen, or any other hormone for that matter, causes lupus.