Celiac disease is caused by the accumulation of celiac fluid in the chest cavity due to blockage or rupture of the thoracic duct. There are various causes of celiac disease, with injury, tuberculosis, filariasis, and tumor causing the most common ones. So how does celiac disease come about? (1) Traumatic: Chest trauma, intrathoracic surgery such as esophageal, aortic, mediastinal or cardiac surgery may cause injury to the thoracic duct or its branches to form celiac disease. Sometimes hyperextension of the spine can also lead to a rupture of the thoracic duct. (2) Tumorigenic: Intrathoracic tumors such as lymphosarcoma, lung cancer or esophageal cancer compress the thoracic duct and obstruction occurs, and the proximal end of the obstructed thoracic duct ruptures due to overexpansion and elevated pressure, causing the thoracic duct or its lateral branch system to rupture. (2 systemic diseases: systemic diseases can be seen in lymphangioleiomyomatosis, thoracic duct lymphangitis, tuberculosis, superior vena cava obstruction syndrome, connective tissue disease (systemic disseminated lupus erythematosus, leukoaraiosis, etc.), nephrotic syndrome, liver cirrhosis, etc. Thoracic duct obstruction caused by filariasis is very rare at present. (3) Congenital: Rarely, the cause is birth injury, or congenital developmental malformation, such as dilatation, defect, thoracic duct atresia or fistula formation, etc.