Pelvic effusion can be asymptomatic or have only mild lower abdominal pain. Physiological pelvic effusion, such as during a woman’s menstrual period, ovulation, or normal plasma secretion from the peritoneum flowing into the pelvic cavity, or a small amount of intestinal fluid flowing into the pelvic cavity in patients with constipation, usually does not cause significant symptoms. In contrast, pelvic fluid caused by diseases, such as pelvic inflammatory disease, ectopic pregnancy, endometriosis and ruptured corpus luteum, may cause different symptoms depending on the disease. 1. pelvic inflammatory disease: mainly manifests as lower abdominal pain, which is easily aggravated after strenuous activities or sexual intercourse, and may also show symptoms such as lumbago and back pain. Acute pelvic inflammatory disease is also accompanied by high fever and chills along with lower abdominal pain; 2. ectopic pregnancy: patients usually have a history of menopause, when the ectopic pregnancy ruptures, there is often a sudden tearing pain in the lower abdomen, accompanied by nausea or vomiting, often accompanied by vaginal bleeding, in severe cases, patients may also faint or shock, requiring emergency medical attention; 3. endometriosis: patients usually have gradually 4, rupture of corpus luteum: patients have a history of lower abdominal impact before menstruation, coughing or strenuous exercise, etc., and it is common to have severe pain on one side of the lower abdomen followed by cramping, which may cause intrapelvic hemorrhage with dizziness, weakness, or even hemorrhagic shock; 5, pelvic or peritoneal tuberculosis: in addition to pelvic fluid and lower abdominal pain, patients usually have menstrual disorders. In addition to pelvic or peritoneal tuberculosis, patients usually have menstrual disorders, and during the active period of tuberculosis, they may have symptoms of tuberculosis poisoning such as low fever and night sweats; 6. pelvic tumor: if the amount of fluid caused by pelvic tumor is small, it may not cause symptoms, but a large amount may produce lower abdominal cramps or pain.