Menstrual period is menstruation, 45 days without menstruation may be due to pregnancy, menopause and other physiological factors, but also polycystic ovary syndrome, cervical adhesions, as well as the uterine cavity adhesions and other factors. 1. Physiological factors: After pregnancy, the estrogen and progesterone content in a woman’s body increases, and there will be menopause, nausea and vomiting and other early pregnancy reactions. In addition, after menopause, the level of hormones in a woman’s body will decrease, and she will experience the symptoms of menopause. All these will lead to women not having menstruation for 45 days, which is a physiological phenomenon and usually does not need treatment. 2. Polycystic Ovary Syndrome: The cause of polycystic ovary syndrome is still unclear, and it is considered to be related to genetic and environmental factors. Patients will have symptoms such as low menstrual flow, amenorrhea, and hirsutism, and so on, so patients will not have menstruation for 45 days. 3. Cervical adhesion: Cervical adhesion may be caused by mechanical damage to the uterine cavity and pathogen infection. The patient may have symptoms such as irregular menstruation, amenorrhea, cyclic abdominal pain, and so on, and thus the patient may not have menstruation for 45 days. 4. Other: Women who do not have menstruation for 45 days are also considered to be caused by uterine adhesion, hypothalamic tumor, ovarian insufficiency and other factors. If it is due to physiological factors, there is no need for treatment. If it is a disease that causes a 45-year-old woman not to menstruate, she needs to consult a doctor in time, and the doctor will clarify the cause of the disease and then carry out the appropriate treatment.