Pelvic free fluid is also called pelvic fluid, 7.9 mm pelvic fluid is generally normal, but if the amount is relatively large, and accompanied by symptoms is abnormal. Pelvic fluid, divided into physiological and pathological, physiological pelvic fluid is mostly seen after ovulation, follicular fluid discharge, then will find a small amount of pelvic fluid, this is a normal physiological phenomenon. Pelvic fluid in pathological cases is mostly related to female pelvic inflammation or tumors, in which case the pelvic fluid is more, usually more than 20 mm. In addition to pelvic effusion, it will also be accompanied by lower abdominal pain, abnormal leukorrhea, etc. In this case, it is recommended to go to the hospital in a timely manner for examination, to clarify the cause of the disease, and then comply with the doctor’s instructions to deal with the treatment.