The most common causes of sinus separation are kidney stones, ureteral stones, pelvic ureteral junction stenosis, prostate hyperplasia or tumors, tumors of the kidney and ureter, and gynecological tumors. The main cause of fluid accumulation is obstruction in the area below the renal pelvis, and there are many reasons for obstruction, the most common of which is stones, while other causes have been mentioned above. Only after these causes are removed can the separation of the renal sinus be relieved. In some cases, the cause of the disease cannot be removed temporarily, such as prostate tumors, gynecological tumors that have metastasized and have no surgical value, so a DJ tube can be placed temporarily to open the urinary tract, which can also relieve the separation of the renal sinus, but the prognosis for these patients is not very good.