1) A chronic, inflammatory, connective tissue disease that can affect the joints and many organs, including the skin, heart, lungs, kidneys, and nervous system. It can cause many different symptoms; however, not everyone with lupus has all of the symptoms.

2) An inflammatory connective tissue disease of unknown cause that occurs chiefly in women and that is characterized especially by fever, skin rash, and arthritis, often by acute hemolytic anemia, by small hemorrhages in the skin and mucous membranes, by inflammation of the pericardium, and in serious cases by involvement of the kidneys and central nervous system -- called also systemic lupus.