Menstruation refers to menstruation, menstruation did not come but has been running water to consider may be related to pregnancy, vaginitis, cervical cancer and so on. 1. Pregnancy: After pregnancy, the hormone level in the body will rise, which will cause the symptom of increased secretion, mainly cervical secretion and vaginal secretion, and some of them will be manifested as running water. 2. Vaginitis: Vaginitis is caused by various pathogens or external stimuli, abnormal hormone levels, etc. It is mainly manifested as abnormal vaginal secretions, such as trichomoniasis vaginitis, which will appear thin purulent secretions, and sometimes it will be manifested as running water, and it is usually accompanied by vulvar itchiness, burning sensation, pain during sexual intercourse, etc. When the symptoms are obvious and serious, it will affect the rest and mood and also lead to delayed menstruation. 3. Cervical cancer: Cervical cancer refers to malignant tumors originating from the cervix, which is related to high-risk HPV (human papillomavirus) infection. In the early stage, there is no obvious symptom, but with the development of the disease, necrotic infection of cervical cancer tissues will cause increased secretion, which will be like running water, and it may be white, bloody and thin, like water, and in some cases it may be accompanied with fishy smell or bad odor. When cervical cancer spreads to the uterus and destroys the lining of the uterus, it may also affect menstruation. There may be other reasons for the absence of menstrual period, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.