Irregular menstruation at the age of 41 may be caused by mental factors, endocrine disorders, gynecological diseases and other factors. 1. Psychological factors: 41-year-old women long time mental tension, anxiety or depression, may have an impact on the hypothalamus, pituitary function, will lead to irregular menstruation, may also appear dysmenorrhea, amenorrhea and other abnormal manifestations. 2. Endocrine disorders: polycystic ovary syndrome, hypothyroidism, pituitary tumors and other factors may lead to endocrine disorders, which may affect the menstrual cycle and make menstruation irregular, manifesting as short or long menstrual cycles. 3. Gynecological diseases: such as endometritis, uterine fibroids, cervical cancer, etc., may lead to irregular vaginal bleeding, which may be mistaken for menstrual flow, and may be accompanied by lower abdominal pain, increased vaginal discharge and other symptoms. At the age of 41 with irregular periods and other abnormalities, it is recommended to go to the hospital for a detailed examination as well as treatment to avoid delaying the condition.