A long-lasting illness that occurs when the immune system attacks its own tissues and organs.

Lupus is long-lasting illness, also known as chronic. Lupus causes swelling, pain, redness and heat, known as inflammation, to the areas it affects. Areas can include joints, skin, kidneys, blood cells, brain, heart and lungs.

Symptoms depend on what areas of the body lupus affects. Symptoms can come on at once or slowly. They can get worse for a while, then get better, known as a flare. Symptoms can include tiredness, fever, skin sores and painful joints.

Treatment for lupus depends on symptoms. Medicines might reduce symptoms.