Menstruation that occurs 3 times a month may be associated with cancer, but it may also be caused by other reasons. Menstruation refers to a series of cyclical changes in the endometrium of the uterus, which is affected by the secretion of estrogen and progesterone by the ovaries, and causes periodic vaginal bleeding, usually in a cycle of about 1 month. If vaginal bleeding occurs 3 times in a month, it is called irregular vaginal bleeding and is mostly due to pathological factors. If it is caused by cervical intraepithelial neoplasia or having cervical cancer, colposcopy and hysteroscopy are needed to clarify the cause and then treat it. In addition, endocrine disorders, dysfunctional uterine bleeding, may also occur with 3 periods in 1 month, and hormone levels, uterine adnexal ultrasound or hypothalamic-pituitary-ovarian axis and other related examinations are recommended. In addition, women who are fertile and not using contraception, if they experience 3 vaginal bleeding in 1 month, they need to consider whether they are pregnant and miscarrying or have an ectopic pregnancy to rule out the possibility of pregnancy. It is recommended that the patient should go to the obstetrics and gynecology department of the hospital in a timely manner for examination to clarify the cause and take appropriate treatment, pay attention to diet and nutrition and avoid straining.