The endometrium is the soil in which the fetus is conceived and is the main component of menstrual blood. It is normally proliferated, secreted and expelled with the menstrual cycle. However, the endometrium can sometimes become restless and appear outside the body of the uterus, which is called endometriosis, or endo. The most common site of endometriosis is the ovaries, followed by the lower posterior pelvic area, such as the uterosacral ligament and the rectal uterine sink. Where do these “misplaced” endometrium come from? It is not completely clear. The most common theory is that it flows backwards into the pelvis with menstrual blood. In recent years, the increased rate of cesarean sections, abortions, and the increased use of hysteroscopic laparoscopy have also led to the introduction of normally located endometrium into other parts of the pelvis. These ectopic endometrium, which also has the function of normal endometrium, will also follow the cycle of bleeding of the normally located endometrium, but since it is not under the complete control of the normally located endometrium, the cycle changes are also more chaotic. Although it is disruptive, it is not as prone to malignant changes as the normal endometrium. When the ectopic endometrium invades the ovary, it can form cyst-like lesions in the ovary containing chocolate-like stale bloody fluid due to repeated bleeding and stimulation of the ovary, hence the name ovarian chocolate cyst. Symptoms of endometriosis Symptoms vary from person to person and are closely related to the location and menstrual status. One-fourth of patients have no symptoms. 1. Dysmenorrhea. The most common symptom. And it is secondary and progressively aggravated dysmenorrhea. Dysmenorrhea is actually a common symptom in many women. Some women have dysmenorrhea starting at menarche, which we call primary dysmenorrhea. This type of dysmenorrhea is usually normal. However, when dysmenorrhea comes from nothing, or when it was already present but keeps getting worse, this should be considered endometriosis. Of course not all patients with endometriosis have dysmenorrhea. 2. Infertility. The infertility rate of endometriosis patients reaches 40% due to the alteration of the pelvic microenvironment caused by ectopic endometrium, which may affect the function of the pelvis and endometrium, etc. 3. Painful intercourse. Seen in endometriosis patients with rectal uterine traps. It is aggravated before menstruation. 4.Other. There are mainly menstrual disorders and acute abdominal pain caused by rupture of chocolate cysts. Endometriosis may appear in other parts of the body with corresponding manifestations. For example, abdominal pain, diarrhea and periodic blood in stool may occur in intestinal endometriosis; painful urination in bladder endometriosis; back pain and hematuria in ureteral endometriosis, etc. Diagnosis of endometriosis A preliminary diagnosis can be made based on symptoms, physical signs and gynecological examination. Ancillary examinations mainly rely on ultrasound, and laparoscopy is required to confirm the diagnosis of endometriosis. In addition, serum CA125 measurement can be used to monitor the efficacy of endometriosis and predict recurrence. Treatment of endometriosis How to deal with these disruptive ectopic endometrium? The main treatment modalities are expectant therapy, drug therapy and surgery. 1. Expectant treatment. Regular follow-up is sufficient for milder symptoms. Painkillers can be used for dysmenorrhea, but those who wish to have children should actively conceive. Although endometriosis can easily lead to infertility, once conception occurs, the endometrium will shrink and the symptoms will be relieved or even cured. 2. Drug treatment. The more commonly used ones are (1) oral contraceptives. Continuous use of the pill can cause a state similar to pregnancy, which becomes a pseudo-pregnancy therapy and can cause the endometrium to atrophy. (2) Progestin: progestin alone is also a pseudo-pregnancy therapy. The above mentioned medication is used for at least 6 months. The main side effects include nausea, vomiting, depression, weight gain, and irregular vaginal bleeding. Menstruation can be restored after stopping the drug. (3) Gonadotropin-releasing hormone agonists (GnRH-a). This type of drug causes suppression of ovarian function and amenorrhea. It becomes a pseudo-menopausal therapy. Commonly used drugs include Norelide and Daphylline. Subcutaneous injections are given once a month, usually 3 to 6 times. Menstruation and ovulation can be restored after stopping the drug. The side effects are mainly various menopausal symptoms, such as hot flashes, night sweats, bone loss, etc. In order to reduce side effects, the drug can be used along with appropriate estrogen supplementation. 3.Surgical treatment. Those who have poor results with medication or larger chocolate cysts or those who have not recovered their reproductive function can be treated surgically. The first choice is the minimally invasive laparoscopy. Try to remove the visible ectopic endothelial lesions or organ removal. Surgery is prone to recurrence and postoperative medications can be used to reduce recurrence. Ovaries and uterus should be preserved in those who need to get pregnant. In those without a need for fertility, the ovaries can be preserved in younger patients, while older patients can undergo radical surgery to remove the ovaries, uterus and pelvic ectopic lesions.