The endometrium undergoes cyclic changes under the combined effect of estrogen and progesterone, also known as the menstrual cycle. In general, the endometrium can be seen on ultrasound. The endometrium is less clear, probably because of the following reasons: 1. near the menstrual period, the endometrium starts to shed near the menstrual period, so it will cause the ultrasound to show less clear. 2. the possibility of polyps in the uterine cavity cannot be excluded, further examination is needed to make a clear diagnosis. 3. it may be due to inflammation of the endometrium, forming endometritis, uterine The endometrium can make the endometrium congested and edematous, accompanied by a large amount of inflammatory exudate, mainly manifested in increased leucorrhea, abnormalities in the nature of leucorrhea, etc. The endometriosis can affect fertility, so once this happens, you need to get further examination as soon as possible, and after the diagnosis is confirmed, you need to get the right treatment to avoid affecting your future pregnancy.