Women get lupus at rate nearly ten times that of men. While it can occur at any age, lupus is most often diagnosed between the ages of 15 and 45 said 44 in opening paragraphs. In the United States, lupus is more common in African Americans, Latinos, Asians, and Native Americans than in Caucasians.

There is some evidence that genetic factors play a role but no single gene has yet been found that causes lupus. Researchers suspect that a person may inherit a predisposition to contracting lupus but that certain environmental factors must also be present in for that person order to get the disease.

Other factors that have been associated with lupus include sun exposure, which may trigger an inflammatory response in certain susceptible people, taking certain prescription drugs, exposure to certain chemicals, and previous infection with the Epstein-Barr virus.