囊性纤维样变性(cystic fibrosis (CF))，亦作黏稠液病（mucoviscidosis）。
一种隐性遗传代谢性疾病，主要侵犯呼吸道、消化道和胰脏，症状是外分泌腺的分泌物过於黏稠，堵塞相应的管道系统。囊性纤维样变性可能是欧洲人中最常见的遗传性疾病，约每2,000个成活婴儿中即有一位。在肺和呼吸道，细支气管被高度黏稠的分泌物堵塞，导致呼吸困难、肺气肿、持续或反覆细菌感染、肺炎、咳嗽、脓痰、进行性肺功能下降、肺心病等，患者最常见的死因是肺病变。在消化道，异常黏稠的消化腺分泌物将消化腺管道堵塞，致使消化液和各种消化不能进入消化道，导致消化和吸收障碍。在多数患者，胰管阻塞会使分泌消化的胰脏腺体产生自我溶解，因此患者常以油腻、恶臭的大块粪便做为发病表徵。此外，由於患者的汗腺无法保留盐分，故可利用汗液含有高浓度盐分来做为诊断依据。治疗方法包括服用胰消化补充物和摄取含高热量、高蛋白和高脂肪的食物，积极的物理治疗以增强各种外分泌腺的功能，视情况服用抗生素以预防或治疗肺部感染。囊性纤维样变性直至1938年才被承认为一种特定疾病，随後被分类为儿科疾病（因其於婴儿期和儿童期死亡率极高），至1980年代中期以後，随着医疗进步，超过半数以上的患者皆可存活至成人。男性成人患者通常伴发不育。
English version：
cystic fibrosis (CF)
Inherited metabolic disorder characterized by production of thick, sticky mucus. It is recessive (see recessiveness) and the most common inherited disorder (about 1 per 2,000 live births) in those of European ancestry. Concentrated mucous secretions in the lungs plug the bronchi, making breathing difficult, promoting infections, and producing chronic cough, recurrent pneumonia, and progressive loss of lung function, the usual cause of death. The secretions interfere with digestive enzymes and block nutrient absorption. Abnormally salty sweat is the basis for diagnosis of cystic fibrosis. Treatment includes enzyme supplements, a diet high in calories, protein, and fat, vigorous physical therapy, and antibiotics. Persons with cystic fibrosis once seldom survived beyond childhood; now more than half reach adulthood, though males are usually sterile.