Systemic Lupus Erythematosus is a complex, chronic autoimmune disease in which the immune system attacks healthy tissue throughout the body. It produces autoantibodies — most notably anti-nuclear antibodies (ANA) and anti-dsDNA — that form immune complexes, triggering widespread inflammation. The hallmark butterfly (malar) rash across the cheeks and nose gives the disease its name: lupus (Latin for wolf) and erythematosus (redness).