A small amount of fluid in the uterine cavity refers to the presence of a small amount of fluid in the uterus, most of which has no pathological manifestations and can be seen in postmenopausal, postmenstrual and post-pregnancy periods. 1. Postmenopausal: Some postmenopausal women may have a small amount of fluid in the uterus, which is mainly due to atrophy or adhesion of the cervical opening, resulting in the endometrial secretion of fluid not being able to flow out of the uterus and forming a uterine cavity, which does not need to be treated without any special circumstances. 2. Menstruation or postmenstrual period: part of the menstrual blood may not be discharged from the uterine cavity in time, resulting in retention of fluid in the uterine cavity during the examination, usually no treatment is needed. 3. After pregnancy: the endometrium’s secretion ability is strengthened, and a lot of fluid will be secreted. At this time, as long as the fluid in the uterus is not bloody, no special treatment is usually needed. Therefore, a small amount of fluid in the uterine cavity needs to consult a doctor in a timely manner, so that the doctor can clarify its specific causes and take targeted treatment.