paroxysmal nocturnal hemoglobinuria
nounMedical Definition of paroxysmal nocturnal hemoglobinuria
: a form of hemolytic anemia that is characterized by an abnormally strong response to the action of complement, by acute episodes of hemolysis especially at night with hemoglobinuria noted upon urination after awakening, venous occlusion, and often leukopenia and thrombocytopenia
—abbreviation PNH