paroxysmal nocturnalparoxysmal hemoglobinurianocturnal hemoglobinuriapheochromocytoma paroxysmparoxysmal hypertensionparoxysmal fibrillationparoxysmal nocturnal haematuriaparoxysmal nocturnal hemolysisparoxysmal nocturnal hematuriadefine paroxysmalnocturnal animals definitionnocturnal emission definition