abnormal bleeding are not related to structural causes. Polyps: Endometrial polyps are benign growths that are typically detected during gynecologic ultrasonography and confirmed using saline infusion sonography or hysteroscopy, often in combination with an endometrial biopsy providing histopathologic confirmation. Endocervical polyps are visible at the time of a gynecologic examination using a vaginal speculum, and can often be removed with a minor office procedure. Adenomyosis: Adenomyosis is a condition in which endometrial glands are present within the muscle of the uterus (myometrium), and the pathogenesis and mechanism by which it causes abnormal bleeding have been debated. Leiomyoma (fibroids): Uterine leiomyoma, commonly termed uterine fibroids, are common, and most fibroids are asymptomatic. The presence of leiomyomas may not be the cause of abnormal bleeding, although fibroids that are submucosal in location are the most likely to cause abnormal bleeding. Malignancy (pre-cancer and cancer): The Malignancy and Hyperplasia category of the PALM-COEIN system includes malignancies of the genital tract, including cancers of the vulva, the vagina, the cervix, and the uterus. Endometrial hyperplasia, included in this PALM category of abnormal bleeding, is more common in women who are obese or who have a history of chronic anovulation. When endometrial hyperplasia is associated with atypical cells, it can progress to cancer or occur concurrently with it. While endometrial hyperplasia and endometrial cancer occur most commonly among post-menopausal women, most patients with endometrial cancer have abnormal bleeding, and thus the diagnosis must be considered in women during the reproductive years. Coagulopathies (blood clotting disorders): Heavy menstrual bleeding can be related to coagulopathies. Von Willebrand disease is the most common coagulopathy, and most women with von Willebrand disease have heavy menstrual bleeding. Of women with heavy menstrual bleeding, up to 20% will have a bleeding disorder. Heavy menstrual bleeding since menarche is a common symptom for women with bleeding disorders, and in retrospective studies, bleeding disorders have been found in up to 62% of adolescents with heavy menstrual bleeding. Ovulatory dysfunction: Ovulatory dysfunction or anovulation is a common cause of abnormal bleeding that may lead to irregular and unpredictable bleeding, as well as variations in the amount of flow including heavy bleeding. Endocrine, or hormonal, causes of ovulatory disorders include polycystic ovary syndrome (PCOS), thyroid disorders, hyperprolactinemia, obesity, eating disorders including anorexia nervosa or bulimia, or to an imbalance between exercise and caloric intake. Endometrial: Endometrial causes of abnormal bleeding include infection of the endometrium,