The common causes for women with unstable periods include physiological factors, ovarian endocrine dysfunction, and other diseases, as follows: 1. Physiological factors: long-term late nights, excessive stress, exertion or environmental changes may cause unstable periods. 2. Ovarian endocrine dysfunction: some women may have ovarian endocrine dysfunction causing unstable periods, which often leads to an early menstrual cycle or a pushed back menstrual cycle. This often leads to early menstrual cycles or pushed back menstrual cycles, and the time of early or pushed back menstrual cycles is usually more than a week. For these women, ultrasound and sex hormone tests may be needed to determine the specific cause. 3. Other diseases: Some women may have polycystic ovary syndrome, but some women may have hyperprolactinemia.