Thin endometrium can cause a decrease in menstrual flow. Low menstrual flow is mainly caused by low estrogen levels or uterine dysplasia. Estrogen can stimulate the endometrium to thicken, and if there is no conception, the hyperplastic endometrium will shed and bleed to form menstruation. Low estrogen level in the body causes the endometrium to be not thick enough, and when menstruation comes, it will show as low bleeding, which may affect conception. If a woman has a thin endometrium, it is recommended to clarify the cause and then target the treatment. If the endometrium is damaged due to miscarriage, further endocrine checks are needed and then targeted conditioning. There are many other causes of reduced menstrual flow in women, such as malnutrition, anemia, mental factors, etc.