Systemic Lupus Erythematosus (SLE) ... is a chronic, autoimmune disease that can damage any part of the body (skin, joints, &/or organs inside the body).
In lupus, something goes wrong with your immune system & can't tell the difference between foreign invaders and your body’s healthy tissues ... creates autoantibodies that attack and destroy healthy tissue ... causing inflammation, pain, and damage in various parts of the body.
Lupus is also a disease of flares (the symptoms worsen and you feel ill) and remissions (the symptoms improve and you feel better).
Chronic means that the signs & symptoms tend to last 6+ weeks to years.