Lupus is an autoimmune disorder that causes the body's immune system to attack its own tissues and organs. The exact cause of lupus is unknown, but it is believed to be related to a combination of genetic and environmental factors. A person can get lupus when their immune system mistakenly attacks healthy tissue and organs in the body, resulting in inflammation and tissue damage. Symptoms of lupus can vary and range from mild to severe. These can include joint pain, fatigue, skin rashes, fever, and organ damage. Treatment for lupus varies depending on the severity of the disease, but can include medications to suppress the immune system, steroids to reduce inflammation, or in some cases, surgery.