Menstruation refers to menstruation, and menstruation that occurs 3 to 4 days early is considered to be related to physiological conditions, endocrine disorders, and so on. 1. Physiological conditions: For women whose menstruation is 3 to 4 days early every time since the onset of menstruation, it may be a physiological condition, which is genetically related to their menstrual cycle, resulting in a menstrual cycle that lasts 26 to 27 days. 2. Endocrine disorders: (1) for often stay up late, work and study stress or recently suffered a major blow to the female, mostly combined with endocrine disorders, so patients will also be early or delayed menstruation and other manifestations, once in a while without too much tension, pay attention to adjusting the lifestyle or replace the more relaxed work. (2) for the past menstrual cycle of normal women, suddenly appeared in the case of persistent early menstruation, be alert to premature ovarian failure, hypothyroidism and other endocrine diseases, due to the patient’s endocrine dysfunction, which in turn affects the normal function of the ovaries and menstrual abnormalities. It is recommended to go to a regular hospital for a complete examination to determine the cause of the disease and then actively treat it.