葡萄糖-6-磷酸脱氢酶缺乏症，又名G6PD缺乏症（英文：Glucose-6-Phosphate Dehydrogenase deficiency），俗称蚕豆症，是一种常见的先天遗传性疾病。患者由于遗传基因的先天缺陷，无法正常地分解葡萄糖。除此以外，部份药物和化学物如蚕豆、樟脑、臭丸、龙胆紫（紫药水）、都会令患者出现急性溶血反应，症状包括黄疸、精神不佳，严重时会出现呼吸急速、心脏衰竭，甚至会出现休克而有生命危险。

Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency) also known as favism (after the fava bean) is an X-linked recessive inborn error of metabolism that predisposes to hemolysis (spontaneous destruction of red blood cells) and resultant jaundice in response to a number of triggers, such as certain foods, illness, or medication. It is particularly common in people of Mediterranean and African origin. The condition is characterized by abnormally low levels of glucose-6-phosphate dehydrogenase, an enzyme involved in the pentose phosphate pathway that is especially important in the red blood cell. G6PD deficiency is the most common human enzyme defect. There is no specific treatment, other than avoiding known triggers.