The cause of lupus remains unknown. Two of the major questions researchers are trying to answer is who gets lupus and why. Understanding what causes lupus could lead to better treatments, cure, or prevention.

A combination of factors may act together to cause lupus. Current scientific thinking focuses on three areas.

  1. Because lupus can run in families, researchers believe that genes play a role. About 50 percent of people who have lupus also have a close relative who has lupus or will develop lupus. Close relative means mother, father, sister, or brother. No single specific lupus gene has been identified.
  2. Hormones may be involved. A link to hormones could explain why lupus occurs more often in females, particularly during their childbearing years.
  3. Something in the environment may cause lupus. Some environmental factors are already known to make lupus symptoms worse. These factors include some prescription drugs and exposure to sunlight.