How thick should the endometrium be for menstruation to occur?
Dec 27, 2023
Source: Cainiu Health
Dr. Zhao Xiaodong
Introduction
Menstruation occurs only when the endometrial thickness reaches a certain level. This is because the endometrium undergoes cyclic changes in response to hormones secreted by the ovaries. The endometrium changes differently throughout various phases of the menstrual cycle. During the first half of the menstrual cycle, the endometrium is in the proliferative phase, with a typical thickness of about 5–6 mm.
Generally, menstruation may occur when the endometrial thickness reaches more than 10mm. The detailed explanation is as follows:
Menstruation occurs only when the endometrium has reached a certain thickness, because the endometrium undergoes cyclical changes in response to hormones secreted by the ovaries. During different phases of the menstrual cycle, the endometrium exhibits various changes. In the first half of the cycle, the endometrium is in the proliferative phase, with a typical thickness of about 5–6mm. During this period, rising estrogen levels cause the endometrium to gradually thicken. In the latter half of the cycle, the endometrium enters the secretory phase and usually thickens to over 10mm, meeting the threshold required for menstruation. Therefore, an endometrial thickness of at least 10mm is necessary for menstruation, primarily because the formation of menstrual blood is closely related to changes in endometrial thickness. Menstrual bleeding results from the shedding of the endometrial lining, which requires sufficient thickness and structural integrity to support normal menstrual flow. If the endometrium is too thin and fails to reach adequate thickness, normal menstruation cannot occur.
Women can follow their doctor's advice to undergo regular color ultrasound examinations to better understand their physical condition.
