If your period doesn’t leave after 25 days, it may be caused by endometrial polyps, fibroids, placement of IUD, endometrial cancer, etc. 1. Endometrial polyps: menstruation means menstruation. Endometrial polyps can cause prolonged menstruation, increased menstrual flow, and also bleeding between menstruation, which can be diagnosed by ultrasonography, and if necessary, need to be removed under hysteroscopy and then pathologic examination can assist in the diagnosis. 2. Uterine fibroid: it can also cause prolonged menstruation, and may also manifest as increased menstrual flow, lower abdominal masses and other symptoms, gynecological examination can touch the uterus to enlarge, the uterine surface can be touched irregularly single or multiple nodular protrusions, combined with ultrasonography can assist in the diagnosis. 3. Placement of intrauterine device (IUD): Placement of IUD is a commonly used contraceptive measure. Irregular vaginal bleeding is the most common side effect, and it can also cause prolonged menstrual period and increased menstrual flow. Ultrasonography or X-ray examination may assist in the diagnosis. 4. Endometrial cancer: It may cause symptoms such as prolonged menstrual period and increased menstrual flow, and may be accompanied by the discharge of foul-smelling fluid from the vagina, etc. Ultrasonography and diagnostic curettage may assist in the diagnosis. When your period doesn’t go away after 25 days, you need to go to the hospital as soon as possible to find out the cause and deal with it positively.