Background. Abnormal uterine bleeding (AUB) is any menstrual cycle disorder that does not meet normal parameters of regularity, frequency, duration, and intensity. AUB are divided into acute and chronic. According to modern paradygm, when describing menstrual disorders, terms “AUB”, “heavy menstrual bleeding”, “intermenstrual bleeding”, “postmenopausal bleeding” should be used.
 Objective. To highlight the role of office hysteroscopy in the treatment of AUB.
 Materials and methods. Analysis of literature sources on this topic.
 Results and discussion. According to the etiology, AUB are classified with the help of PALM-COEIN system: P – polyp, A – adenomyosis, L – leiomyoma, M – malignancy and hyperplasia (causes of structural disorders), C – coagulopathy, O – ovulatory dysfunction, E – endometrial dysfunction, I – iatrogenic causes, N – causes not established (causes not related to structural disorders). At different ages, the main causes of AUB are different (in childhood – injuries, infections, ovarian tumors, in childbearing age – anovulation, pregnancy, endocrine disorders, in old age – endometrial cancer). When examining patients with AUB, one should carefully collect a history, carry out physical and gynecological examination, determine the condition of the thyroid gland, exclude coagulopathy and pelvic diseases. Office and even portable hysteroscopy is a modern method of visual diagnosis of AUB. Techniques for hysteroscopic removal of intrauterine pathological formations include curettage under the control of a hysteroscope, removal with forceps or laser, hysteroresectoscopy, intrauterine morcelation. Office hysteroscopy can successfully detect and treat polyps, leiomyomas, isthmocele, chronic endometritis, hyperplasia. AUB is often accompanied by iron deficiency anemia (IDA). In severe cases or in the case of planned surgical interventions, IDA require treatment with intravenous iron preparations. Clinical data show that patients with preoperative anemia treated with iron preparations before surgery do not require blood transfusions in the postoperative period. Sufer (“Yuria-Pharm”) is a trivalent iron for intravenous administration. The dose is calculated individually for each patient based on the level of hemoglobin and the severity of iron deficiency. In case of severe blood loss during the operation, it is advisable to use tranexamic acid (Sangera, “Yuria-Pharm”), which is 10 times more effective than ethamsylate and 26 times – than aminocaproic acid. In a multicenter, randomized, double-blind, placebo-controlled WOMAN study of 20,000 women with postpartum haemorrhage, tranexamic acid reduced fatalities by more than 30 % and the need for urgent surgery for hemostasis by more than 35 %.
 Conclusions. 1. AUB can have different etiology, which largely depends on the age of the patient. 2. Office hysteroscopy is a promising method of visualization diagnosis and treatment of AUB. 3. Intravenous iron preparations can be used to correct anemia after AUB, and tranexamic acid – to stop an excessive bleeding.