Endometrial hyperplasia can be divided into simple hyperplasia, complex hyperplasia and atypical hyperplasia based on the degree of proliferation and differentiation of cellular morphology and glandular structure, and atypical hyperplasia is now divided into simple and complex atypical hyperplasia. Some studies have shown that the probability of developing endometrial cancer from simple or complex hyperplasia is 1% and 3%, respectively, and the average progression time is about 10 years, while the probability of developing endometrial cancer from simple and complex atypical hyperplasia is 8% and 29%, respectively, and the average progression time is 4.1 years. Currently, WHO considers endometrial atypical hyperplasia as endometrial precancerous lesions. 1. Diagnosis: Since patients with endometrial hyperplasia mostly have no specific symptoms or signs, they need to confirm the diagnosis with the help of relevant auxiliary examinations. 1.1 Clinical manifestations: The prominent symptom of endometrial hyperplasia is abnormal menstruation, mostly manifested as irregular vaginal bleeding, often anovulatory gonorrhea, which may be combined with secondary anemia in those with more bleeding. Young patients may have infertility and obesity, and up to 22%-66% of patients with atypical hyperplasia are infertile, including 90% of those under 40 years of age with combined infertility. Patients with complex hyperplasia and atypical hyperplasia often have no abnormalities on physical examination, while those with prolonged vaginal bleeding have an anemic appearance. The gynecologic examination is usually unremarkable, but in a few patients, the uterus is slightly enlarged, and in those with polycystic ovaries or functional ovarian tumors, enlarged ovarian or adnexal masses can be found. 1.2 Histological examination: Histological examination is the confirmatory method for the diagnosis of endometrial hyperplasia. Methods of obtaining tissue specimens include endometrial scraping and biopsy, dilation and curettage, negative pressure aspiration and hysteroscopic biopsy. Complex endometrial hyperplasia and atypical hyperplasia can be scattered or single focal lesions, and sometimes coexist with endometrial cancer, so the entire surface of the uterine cavity must be obtained to confirm the diagnosis. Although scraping is more comprehensive than endometrial biopsy, it is a blind operation and endometrial tissue may be missed in areas not reached by the scraping spoon, especially at the uterine horn and fundus. Negative pressure suction can make the endometrium fall off completely, which is relatively more comprehensive and reliable, but it is less used at present because it is more traumatic to the endometrium. Hysteroscopy: It is the examination and diagnostic analysis of diseases in the uterine cavity through hysteroscopy, which can directly observe the endometrial condition and scrape the endometrial tissue under direct vision, making the diagnosis more comprehensive and making up for the shortcomings of traditional scraping methods. Hysteroscopic biopsy has now become the recognized gold standard for the diagnosis of uterine cavity diseases. 1.3 Other ultrasound examinations (including abdominal ultrasound, vaginal ultrasound, uterine ultrasound, etc.) can understand the thickness of the endometrium and the presence of occupying lesions in the uterine cavity, and can clarify the condition of both adnexa and detect ovarian lesions in a timely manner. Basal body temperature measurement can give a general idea of ovulation and luteal function. Measurement of serum hormone levels can indicate the presence of polycystic ovaries, ovarian endocrine tumors, pituitary tumors, etc. The treatment of patients with endometrial atypical hyperplasia should firstly clarify the diagnosis, the cause of the abnormal hyperplasia, the presence of polycystic ovaries and other endocrine disorders, and if any of these conditions are present, treatment should be directed at the cause. In young patients expecting to be born, more emphasis should be placed on drug treatment. 30% of patients can conceive and give birth in full term after treatment. Hysterectomy is recommended for pre- and post-menopausal women with a greater propensity for cancer than the younger ones. 2.1 Pharmacological treatment 2.1.1 Progestins: Progestins can counteract estrogen-induced endometrial hyperplasia by reducing serum estradiol levels through hypothalamic and pituitary inhibition of ovulation and gonadotropin release on the one hand, and reducing endometrial estrogen nuclear receptor levels on the other. 45 studies of progestins in the treatment of complex atypical hyperplasia were conducted by Camille et al. The results showed that the initial response rate of patients with complex atypical hyperplasia to treatment was 85.6%, with a sustained response rate of 65.8%, a recurrence rate of 23.2% and a lesion persistence rate of 14.4% after administration of progestins including medroxyprogesterone acetate, megestrol acetate, intramuscular 17-hydroxyprogesterone, oral contraceptives, norethindrone and natural progestins. After this treatment 41% of patients conceive spontaneously or through assisted reproductive techniques. Oral progestin is also one of the most common treatments for complex endometrial hyperplasia in young women. The method of progestin administration and dose vary according to the degree of endometrial atypical hyperplasia. For mild atypical hyperplasia, progesterone 20-40mg intramuscularly or progesterone gel 100mg twice a day orally, starting on day 18 or 20 of the menstrual cycle, is usually used for 5-7 days. For moderate to severe atypical hyperplasia, continuous use of progestin preparations such as medroxyprogesterone acetate 250mg or medroxyprogesterone 160mg is recommended. After 3 months of continuous use, the endometrial mold is scraped for histological examination, and the drug is discontinued or added or subtracted according to the results. 2.1.2 LNG-IUSLNG-IUS: 20µg of levonorgestrel is released directly into the uterine cavity daily, producing higher endometrial concentrations and lower plasma concentrations, with only minor side effects on the body’s metabolism. It was found that in young women using LNG-IUS, serum concentrations of LNG reached a steady state of 332 pg/ml after 6 months. LNG-IUS is effective in both complex hyperplasia and atypical hyperplasia, with most patients achieving improvement within 12 months, and LNG-IUS has been recognized as a successful treatment in much of the literature. 2.1.3GnRH-aGnRH analogue (GnRH-a): inhibits endogenous estrogen, while GnRH-a has a direct antiproliferative effect on endometrial cells.Kullander first elevated the use of GnRH-a for the treatment of endometrial hyperplasia to theory in 1992.Grigoris et al. found that treatment of endometrium with GnRH-a The rate of improvement after 6 months for simple and/or complex hyperplasia was 86%, which was comparable to the effect of progestin therapy, while the treatment of atypical hyperplasia was less effective. 2.2 Surgical treatment: Patients with atypical hyperplasia in young women are generally not treated surgically, especially those who have not completed their reproductive function. If medication is ineffective or recurs after discontinuation of medication, and patients without reproductive requirements may consider hysterectomy. This is because after progestin therapy, about 25% of patients may have undiagnosed cancer and about 29% of patients will progress to cancer. After conservative drug treatment for patients with fertility requirements is ineffective, individual reports may choose hysteroscopic lesion resection, but patients must give informed consent and be closely followed up. 2.3 Monitoring and follow-up prevention: 3 months is one course of drug treatment for patients with endometrial atypical hyperplasia. After each course, endometrial pathological examination by scraping is required to monitor the effect of drug treatment and disease regression and adjust the dose of drugs. Since endometrial atypical hyperplasia has the possibility of progressing to endometrial cancer, young patients without hysterectomy should be followed up for a long time even after the hyperplasia has subsided.