Vacation refers to menstruation. If the endometrium is 0.4cm, there may be physiological and pathological cases, if it is physiological case, it can be left untreated; if it is pathological case, such as uterine adhesion and endocrine disorders, it should be treated according to the cause of the disease, and it may be treated with hysteroscopy or estrogen-progestogen sequential treatment, and so on. 1. Physiological situation: perimenopausal endometrium 0.4 cm without menstruation is a normal physiological situation, and no intervention can be made. 2. Uterine adhesion: mostly caused by improper operation in the uterine cavity, such as excessive scraping and other injuries to the endometrial basal layer of the uterus, given to the hysteroscopic adhesion separation surgery, and after the operation in the uterine cavity in the balloon or on the birth control ring, and oral estradiol and progesterone and other medications. 3. Endocrine disorders: the diagnosis can be confirmed by sex hormone six tests, followed by estrogen-progestin sequential treatment such as estradiol valerate with progesterone, etc., which can not only make the endometrium grow normally, but also make the menstruation regular, with a course of treatment of about 3~6 months. Endometrium 0.4cm without menstruation may have other reasons, should promptly go to the hospital and do the relevant examination to clarify the cause of the disease, under the guidance of the physician treatment, do not unauthorized treatment, in order to avoid misunderstanding the condition, resulting in a bad outcome.