It is considered normal to have a menstrual cycle of 3-7 days. The vast majority of women have their periods for 3-5 days, and it is not good to have a short or long period. If your period lasts less than 3 days or just a little bit, you should consider whether you have cervical or uterine adhesions. In addition, women with endocrine abnormalities or hypothyroidism may also have a low menstrual flow. If the menstrual flow is more than 7 days, it is also necessary to consider whether there are fibroids, endometrial polyps or functional uterine bleeding. For this category of patients, diagnostic curettage or hemostatic treatment is needed aggressively.