Endometriosis is a common estrogen-dependent disease in women of reproductive age, with an incidence of 15-20%. In recent years, its incidence has been on the rise, becoming a “modern disease” and a “multi-morbidity”. Although endometriosis is a benign lesion, it has biological characteristics similar to malignant tumors, such as local invasion, distant dissemination, and easy recurrence. The pathogenesis has not yet been completely elucidated, and the most effective diagnostic methods are still being explored. The clinical manifestations of endometriosis are: 1. Symptoms: The most common symptoms of endometriosis include lower abdominal pain, dysmenorrhea, sexual discomfort and infertility, while about 30% of patients have no obvious conscious symptoms. (1) Lower abdominal pain and dysmenorrhea: The pain is mostly located in the deep lower abdomen and rectal area, mostly in the middle of the pelvis, and can also involve both sides of the pelvis and the pelvic wall. Secondary dysmenorrhea is a typical symptom of endometriosis, which mostly increases gradually with the aggravation of local lesions. It often appears at the beginning of menstruation and lasts throughout the menstrual period. And the degree of pain is not necessarily proportional to the size of the lesion. (2) Discomfort during sexual intercourse: Mostly seen in patients with ectopic lesions in the rectal uterine trap or posterior fixation of the uterus due to lesions, usually manifesting as deep intercourse pain, which is more pronounced before the onset of menstruation. (3) Infertility: The infertility rate of endometriosis is as high as 40%-50%. The causes of infertility are complex, such as changes in the pelvic environment affecting the union of sperm and egg; adhesions in the pelvis, fallopian tubes and ovaries affecting the transport of fertilized eggs or embryos, etc. (4) Menstrual abnormalities: 15%-30% of patients have increased menstrual flow, prolonged menstrual period or premenstrual spotting. The abnormal menstruation may be related to the destruction of ovarian tissue by the lesion, affecting ovarian function. Some patients may have a combination of adenomyosis or fibroids. (5) Other special symptoms: abdominal pain, diarrhea, constipation, and even a small amount of periodic blood in the stool may occur in intestinal endoheterosis, and intestinal obstruction may occur in severe cases; urinary endoheterosis may cause back pain, hematuria, and hydronephrosis; abdominal wall scar endoheterosis may cause periodic pain at the site of the lesion and a mass may be found. The clinical manifestations of extra-pelvic endometriosis are mainly related to the location of the endometriosis lesion. In addition, the rupture of ovarian ectopic cysts can cause sudden and severe abdominal pain with nausea and vomiting, anal swelling and other acute abdominal manifestations. 2.Signs Except for huge ovarian endometriosis cysts, which can be found in the abdomen and the signs of peritoneal irritation when the cyst ruptures, there are no obvious abnormalities in the abdominal examination, and typical pelvic endometriosis can be found in the pelvic examination with the uterus posteriorly positioned and inactive, adnexal masses adherent and inactive, mostly located in the posterior uterus, posterior uterine wall and bilateral uterosacral ligaments, and painful nodules can be palpated in the pelvic floor. Cystic inactive masses with adhesions to the uterus or broad ligaments are found on one or both sides of the uterus, often with light pressure pain. If the lesion involves the rectovaginal septum, a small raised nodule or mass may be found in the posterior vaginal fornix, and sometimes even a localized raised blue spot or nodule may be seen directly.