What is the reason for women's early menstruation

Menstruation ahead of time, one is endocrine, that is, ovulation ahead of time, menstruation ahead of time, cycle change, each person normal is 23~28 days, but individual patients cycle shortened, ovulation time also changed, thus causing cycle shortening, endocrine diseases. Menstruation cycle as long as more than 23 days, it is not ahead of schedule, not to say 28 days a cycle, one week ahead or one week behind, are considered in the normal range, so do not interfere, if ten days ahead of schedule to menstruation, is dripping bleeding, you need drug intervention, but also need to check the cause of diagnosis and treatment.