Patients with unusually heavy bleeding two days before menstruation are caused by uterine fibroids, adenomyosis, and abnormal uterine bleeding. Some patients with uterine fibroids do not have any symptoms, but the most typical symptoms of uterine fibroids are increased menstrual flow and prolonged menstrual period. Patients with adenomyosis can lead to an increase in the endometrial area, so they can have symptoms of increased menstrual flow and prolonged periods. Abnormal uterine bleeding is an endocrine disorder after excluding organic lesions, and all three of these conditions can lead to excessive menstrual bleeding. For uterine fibroids and adenomyosis, ultrasonography is an assisted diagnostic method. If the ultrasound does not suggest the presence of organic lesions in the uterus, a blood test for hormone 6 is needed to understand the secretion of various hormones. In summary, the patient can make a clear diagnosis and develop the next treatment plan based on the ultrasound and laboratory findings.