The most common cause of chylothorax is when the thoracic duct accidently gets damaged during a thoracic surgery, but it can also be caused by tumors in the mediastinum that press up against the thoracic duct and compress it shut.

乳糜胸的常见病因是胸部手术中胸导管意外损伤，也可能是纵膈肿瘤压迫胸导管使其闭合。