What causes lupus?

We don’t know what causes lupus. There is no cure, but in most cases lupus can be managed. Lupus sometimes seems to run in families, which suggests the disease may be hereditary. Having the genes isn’t the whole story, though. The environment, sunlight, stress, and certain medicines may trigger symptoms in some people. Other people who have similar genetic backgrounds may not get signs or symptoms of the disease. Researchers are trying to find out why.