Whether the endometrial thickness of 7mm is normal or not depends on the period of menstruation. If it is in the middle of the menstrual period, it is slightly thin, if it is in the middle of the menstrual period, it is normal, and if it is in the middle of the end of the menstrual period, it is slightly thicker. Generally, the endometrium is thickest at around 10-12mm before menstruation, and thinnest at the end of menstruation, and then gradually repairs and thickens under the effect of estrogen. The endometrium is usually thickest before menstruation, usually around 10-12mm, and the endometrium sheds blood to form menstruation. If the endometrium is 7mm at this time, which is a thin condition, you may have short periods, low menstrual flow, easy to miscarry, etc. The reasons include low level of estrogen secreted by the ovaries, previous uterine operations destroying the endometrium, and nutritional deficiencies, which need to be adjusted and treated under the guidance of a doctor. Generally, the endometrium is about 5mm at the end of the menstrual period, which is the thinnest period. If the endometrium is 7mm thick at this time, which is a slightly thicker situation, prolonged vaginal bleeding or heavy bleeding may occur, and it is necessary to go to the regular hospital as soon as possible to check whether there are endometrial polyps, endometrial hyperplasia, or even malignant changes and other diseases. In addition, if a woman has polycystic ovary syndrome, the endometrium will continue to be subjected to estrogen for a long period of time, and the endometrium will be in a proliferative state for a long period of time, which will also result in endometrial thickening. If there are abnormalities in the amount and duration of menstruation, or abnormal thickness of the endometrium, it is recommended that the woman consult a regular hospital in time to identify the cause of the disease and then actively treat it under the guidance of a professional doctor.