Female pelvic fluid may have physiological pelvic fluid during menstruation and ovulation, or it may be pathologic pelvic fluid caused by inflammation. 1. Physiological pelvic effusion: it mostly occurs in women during menstruation and ovulation, because the pelvis is the lowest anatomical site, and when there is a small amount of exudate fluid from the pelvic and abdominal organs, it will firstly accumulate in the pelvis, forming pelvic effusion. 2. Pathological pelvic fluid: most of the pathological pelvic fluid is caused by inflammation, if women do not pay attention to hygiene during menstruation may lead to uterine infection, causing pelvic fluid. Some women have undergone uterine surgery, which can also lead to infection and cause pelvic effusion. Infections in neighboring organs, such as appendicitis, can also develop pelvic fluid. Physiological pelvic fluid usually does not need to be treated. Pathological pelvic fluid suggests that women go to the hospital to find out the cause of the condition and standardize treatment. There may be other causes of pelvic effusion, and women are advised to go to the hospital for detailed examination.