If the menstruation always comes and goes, dripping, indicating menstrual disorders, resulting in the menstruation has not been clean, the more common reasons are as follows: First, unstable ovarian function, endocrine disorders, if the ovary secretes hormone levels are not stable, resulting in hormone level disorders in the body, or have polycystic ovary syndrome, will cause irregular menstruation. Second, if there are uterine fibroids, or endometrial inflammation, it will also affect menstruation. Third, some women have a birth control ring, the birth control ring if the endometrial stimulation is more obvious, can also lead to the menstruation is not always clean. Fourth, abnormal endometrial hyperplasia, like functional uterine bleeding can also lead to irregular menstruation, for which timely examination and treatment are needed.