What causes menstrual cycle length?

In general, women's menstrual cycle is 21 days to 35 days, menstrual cycle as long as this range is normal. If the menstrual cycle is more than 35 days, it indicates that the menstrual cycle is too long. Menstruation cycle is too long and hormone deficiency in the body, polycystic ovary syndrome or hyperprolactinemia and other endocrine diseases, there are also some women due to uterine adhesions and other diseases caused, want to understand the specific reasons, it is recommended to do sex hormone six, B ultrasound and other examinations, clear the type of disease, degree, follow the doctor's advice for treatment. Suspected uterine adhesions, but also need to do hysteroscopy, diagnosed after the general is to go through surgery treatment.