Endometrial thickness of 4mm has no special significance, it means that currently is the thickness of the endometrium is 4mm, however, whether this thickness is normal or not, is to be judged according to the period in which it is located.
There are three phases in the menstrual cycle, which is divided into proliferative phase, secretory phase and menstrual phase, and the thickness of the endometrium is different in different periods.
1. Proliferative phase: generally on the 5th-14th day of menstruation, the thickness of the endometrium in this phase generally increases from 0.5mm to 3-5mm.
2. Secretory phase: generally on the 15th-28th day of menstruation, at this time, due to hormone level stimulation, the endometrium will further thicken to about 10mm.
3. Menstrual period: on the 1st-4th day of menstruation, the endometrium will gradually shed and become thinner again.
So 4mm of endometrium does not mean anything, if there is any abnormality in the usual way, then you can seek medical advice to find out the cause.