What is the reason for the aunt's advance?

Normal women's menstrual cycle is generally about 28 days to once, some women may be four or five days in advance, if every time is like this, this is often normal. Menstruation cycle shortened, because the follicular phase shortened, that is, follicle growth speed is faster, this does not affect women's reproductive function, also does not affect women's endocrine, as long as every time is constant to come, then it is normal phenomenon. However, if the menstrual cycle is too short less than 22 days to come once, then this case is often caused by the premature atrophy of the corpus luteum in the body, which requires medication. Because menstruation is too frequent, it is easy to cause female anemia.