The endometrium varies with the hormone levels in the body. If the endometrium is 4-5 mm thick during menstruation, if it is higher than this value, it is considered to be too thick, which is mostly seen in dysfunctional uterine bleeding and endometritis. If it is lower than 4 mm, the endometrium is too thin, which is seen after multiple abortions or multiple scrapings. The endometrium can reach 9 mm during ovulation, and menstruation occurs when the endometrium thickens to 10 mm. Both too thin and too thick endometrium can affect the fertilization of eggs and lead to infertility. When the endometrium is abnormal, you need to go to the gynecology department of the hospital in time to find out the cause and then treat the problem. It is important to use contraceptive measures to avoid abortion after an unwanted pregnancy, which can damage the endometrium. If there is gynecological inflammation, it needs to be treated in time.