The difference between early and late menstruation

Normal adult female menstrual cycle is 28 days, one week in advance or delayed within a week, as long as there is no menstrual blood volume, color, abnormal characteristics, are normal phenomena, if more than a week in advance, generally gynecological inflammation and endocrine disorders caused, such as ovarian dysfunction, luteal insufficiency caused, these will cause menstruation ahead of schedule. Menstruation delay more than a week, if there is normal sex life, first consider pregnancy, exclude pregnancy, the most common polycystic ovary syndrome, or suffer from metabolic diseases, such as thyroid dysfunction, can cause menstruation delay, in addition to mental factors.