Endometriosis is the ectopic growth of endometrial glands and mesenchyme outside the uterine cavity, forming foci and causing symptoms. Due to its invasive growth, it often involves the organs around the cervix, leading to associated signs and symptoms. Ureteral endometriosis refers to the ectopic growth of endometrial glands and mesenchyme around the ureter, encircling and compressing the ureter, and even invading the ureteral muscular layer and mucous membrane, causing ureteral stenosis or obstruction, leading to dilatation of the ureter and renal pelvis above the site of obstruction and accumulation of fluid, and over time, the renal cortex shrinks due to the compression of renal pelvis accumulation of fluid, resulting in loss of renal function, and the loss of renal function due to renal cortical atrophy is often irreversible. The decline is often irreversible, and even if the ureteral obstruction is lifted, renal function cannot be restored to the normal level. Ureteral endometriosis is often located in the pelvic section of the ureter, especially in the area where the ureter crosses the uterine artery, and there are two types of endogenous and ectogenous, the former refers to the growth of the lesion around the ureter, encircling and compressing it, with a normal ureteral wall. The latter means that the lesion invades the ureteral muscular layer and even the ureteral mucosa, destroying the structure of the ureteral wall. Both can cause ureteral obstruction. Ureteral obstruction caused by endometriosis is often unilateral and is more common on the left side. Ureteral endometriosis does not have its own specific symptoms and often has only the clinical manifestations of endometriosis, with dysmenorrhea, painful intercourse, and infertility predominating. Endometriosis causing ureteral obstruction often results in the formation of large nodules in the pelvis, which are often located lateral to the cervix and grow along the sacral and main ligaments toward the pelvic wall, and in some patients the nodules may extend to the pelvic wall. In most patients, the nodules are tender to touch, and in a small number of patients, the nodules are not tender to touch, and the nodules cannot even be touched if the obstruction is high. Transvaginal examination of the lateral fornix in some patients shows purple-blue nodules, and the vaginal mucosa can be intact in some patients. Because ureteral endometriosis has no specific symptoms of the urinary tract, and due to the compensatory effect of the healthy side of the kidneys, the patient does not have urinary oliguria, blood urea nitrogen and creatinine elevation and other manifestations of renal insufficiency, so that the patient and the doctor are often concerned about dysmenorrhea and infertility treatment, but ignored the examination of the presence of obstruction in the urinary tract until the discovery of severe ureteral effusion when it is suspected that ureteral obstruction is caused by endometriosis. This is the main reason why endometriosis causes “silent” loss of renal function. Ureteral endometriosis is difficult to diagnose when it does not cause ureteral obstruction with hydronephrosis, and often requires surgery to determine the relationship between the endometriosis lesion and the ureter. Once the ureteral obstruction is caused, the diagnosis is very easy. Ultrasound, CT, MRI and other imaging tests can find dilated hydronephrosis on the affected side of the renal pelvis and ureter, combined with the patient’s clinical manifestations of endometriosis and signs such as painful nodules, the diagnosis of ureteral endometriosis can basically be established. The treatment of ureteral endometriosis should be carried out early when it has not caused ureteral obstruction of fluid accumulation, and it is crucial to remove the lesion tissue around the ureter and loosen the ureter to avoid obstruction, which requires that we should pay attention to the unobstructed ureter when we do the surgery for endometriosis, and remove it if there is a lesion present in its surroundings to avoid it from progressing to cause obstruction of the ureter and lead to the decline of renal function and the renal function quietly lost. When the endometriosis lesion invades the ureter and ureteral obstruction has occurred, ureteral resection of the focal segment, ureteral anastomosis, or ureteral bladder implantation may be performed. Although the obstructed ureter can be reopened, it is impossible to restore the lost kidney function to normal.