Early menstruation with small amount of dark brown color is considered to be caused by endocrine disorders, gynecological inflammation, taking birth control pills and so on. 1. Endocrine disorders: when a woman grows older or has insufficient nutritional intake, nervousness, emotional changes, environmental changes, etc., can lead to hormone secretion imbalance, which leads to menstrual disorders, and can also cause early menstruation, low volume, dark brown color and other phenomena. 2. Gynecological inflammation: such as common endometritis, cervicitis, etc., due to the stimulation of inflammation, may lead to menstrual cycle disorders, may also cause early menstruation, as well as the phenomenon of low volume and dark brown color. 3. Taking contraceptive pills: If women often take contraceptive pills, it may affect the normal estrogen and progesterone secretion in the patient’s body, thus affecting the menstrual cycle and leading to menstrual disorders, which may result in such abnormal manifestations as early menstruation, low menstrual flow and dark brown color. Early menstruation, low menstrual flow and dark brown color may also be caused by other reasons, it is recommended to go to the hospital in time to identify the causes, and under the guidance of the doctor to carry out reasonable treatment.