Sudden bleeding similar to menstrual flow may be caused by abnormal bleeding during non-menstrual periods, such as endocrine hormone disorders, polycystic ovary syndrome, or irregular menstruation due to increased prolactin. The above mentioned bleeding may occur in cases of cervical polyps including precancerous lesions and viral infections. The first thing is to go to the gynecology department to do an ultrasound to rule out any abnormalities in the uterus and adnexa, if there is no big problem, you can take certain oral anti-inflammatory and hemostatic drugs according to the situation to help the uterus return to its normal form, and observe whether there is such a situation occurring in the future, if not, there is no big problem, and a simple occurrence will not affect health; If there is still next month, this time to check the endocrine hormone, to exclude the presence of endocrine hormone disease, according to the situation can take oral short-acting contraceptive drugs to regulate.