Abnormal uterine bleeding (AUB) is the most common gynecological problem. The causes of bleeding are various and depend on the age of women. The inconsistency of nomenclature and classification of causes limits their effective use in medical communication and researches. In the year 2010. The International Federation of Gynecology and Obstetrics (FIGO) accepted new classification based upon the causes of bleeding and named it „PALM-COEIN classification“. The acronim PALM-COEIN stands for first letters of causes of abnormal bleeding (polyps, adenomyosis, leiomyoma, malignancy and hyperplasia–coagulopathy, ovulatory disorders, endometrial causes, iatrogenic, not classified). The investigation of abnormal uterine bleeding consists of medical history, physical and gynecological examination, gynecological ultrasonographic imaging and laboratory examination. History helps us to determine the frequency, predictability and the volume of bleeding and gynecological, sonographic and laboratory examination helps us define the causes of abnormal uterine bleeding. The therapy of abnormal uterine bleeding depends on emergency, causes of bleeding, the age of women, future reproductive wishes, possible outcomes, family and personal risks and the effectivness of former treatment. Treatment can be conservative medical therapy or surgical. The treatment of nonstrucural causes of abnormal uterine bleeding is usually medical, and surgical treatment is the first option in simptomatic structural causes of bleeding. All bleeding unresponsive to medical therapy is also treated surgically.