At the age of 48, menstruation lasting for one month may be caused by perimenopausal syndrome, uterine fibroids, adenomyosis and other diseases, or endometrial cancer and other diseases. 1. Perimenopausal syndrome: Perimenopausal syndrome is caused by the failure of ovarian function, and patients will have symptoms such as menstrual disorders, long duration of menstruation, hot flashes and insomnia, etc., and the patients will show symptoms of menstruation lasting for one month. 2. Uterine fibroids: Uterine fibroids are caused by heredity, sex hormones and other factors, and the main symptoms of patients are prolonged duration of menstruation, dysmenorrhea, leukorrhea, and lower abdominal distension. As a result, patients may experience menstruation lasting for a month. 3. Adenomyosis: Adenomyosis is considered to be caused by the invasion of the endometrium of the basal layer of the uterus into the myometrium to grow, and patients will have increased menstrual flow, prolonged menstruation, dysmenorrhea, etc., and they will also have the symptom of menstruation lasting for one month. 4. Other: endometrial cancer, endometritis, endometrial polyps and other diseases can also lead to the phenomenon of menstruation lasting one month. If a female patient at the age of 48 has the symptom of menstruation lasting for one month, it is recommended to consult a doctor in time and follow the doctor’s instructions.