Women’s menstrual period 15 days ahead of schedule has more reasons, need to be accurately diagnosed, the common causes are as follows: 1, endocrine abnormalities: women excessive tension, anxiety, emotional and endocrine abnormalities, affecting the time of menstruation. Therefore, environmental and mental changes are drastic, triggering endocrine disorders and functional uterine bleeding; 2. Ovulation: women’s menstruation 15 days early may belong to the ovulatory uterine bleeding; 3. Gynecological diseases: gynecological diseases, such as ovarian cysts, uterine fibroids, cervical erosion, cervical polyps and so on, can cause abnormal functional uterine bleeding, which manifests itself as women’s menstruation early. If these problems occur only occasionally, observation is sufficient. If menstruation occurs more frequently, such as 15 days before menstruation, it is necessary to accurately diagnose the specific cause and intervene as soon as possible to avoid delaying the condition.