What is the normal thickness of the endometrium in millimeters?
Jul 10, 2025
Source: Cainiu Health
Dr. Zhang Lu
Introduction
Under normal circumstances, the thickness of the endometrium typically ranges from 1 to 16 mm. This value is not fixed, but rather varies according to the menstrual cycle and the physiological stage of the female. The thickness of the normal endometrium is a dynamic range influenced by the menstrual cycle and the woman's physiological stage. Therefore, when evaluating endometrial thickness, it should be interpreted in conjunction with these factors.
Generally, the thickness of a normal endometrium typically ranges from 1 to 16 mm. This measurement is not fixed but varies according to the menstrual cycle and the woman's physiological stage. Detailed analysis is as follows:
During the menstrual cycle, right after menstruation ends, the endometrium—which has shed—is at its thinnest, usually measuring 1–4 mm. As the proliferative phase progresses, the endometrium gradually thickens under the influence of estrogen, reaching approximately 8–10 mm at ovulation. During the secretory phase, it continues to thicken further under the influence of progesterone and may reach 10–16 mm just before menstruation. From the perspective of a woman's physiological stages, in adolescence, endometrial thickness gradually stabilizes as the reproductive system develops. In women of reproductive age, the endometrium shows cyclical fluctuations due to periodic hormonal changes. In postmenopausal women, the endometrium becomes significantly thinner due to decreased estrogen levels, typically not exceeding 4 mm. These variations are normal manifestations of the endometrium adapting to physiological demands.
The normal thickness of the endometrium is a dynamically changing range, influenced by both the menstrual cycle and the woman's physiological stage. Therefore, when assessing endometrial thickness, individual circumstances should be considered. If you have any concerns or experience abnormal symptoms, it is recommended to seek timely medical advice from a qualified healthcare professional.
