Lupus (systemic lupus erythematosus, or SLE) is a long-term autoimmune disease, in which the immune system attacks normal body tissues as though they were foreign substances, causing inflammation and tissue damage throughout the body. Symptoms include fatigue, fever, skin rashes, and muscle and joint pain.

Inflammation caused by lupus can affect the skin, the joints, and most other organ systems in the body, including the kidneys, heart, lungs, and nervous system. It causes a variety of symptoms depending on which organ systems are affected and how severely they are affected.

Some people may have severe episodes; others have a milder form of the disease. Symptoms of lupus may come and go in episodes called flares. There is no cure for lupus. Home treatment and, if needed, medications to control inflammation are the primary treatments.

The most common and serious type of lupus is systemic lupus erythematosus (SLE); the four other types are discoid/cutaneous, subacute cutaneous, drug-induced systemic, and neonatal lupus. Lupus is more common in women than in men.