Pelvic fluid usually has two kinds: physiologic and pathologic. Physiologic pelvic fluid symptoms are not obvious and usually accompanied by mild abdominal pain. The pain of pathologic pelvic effusion usually manifests as vague pain and distension on one or both sides of the lower abdomen, or pressure pain and rebound pain. Severe cases may involve low back pain and should be treated promptly. Physiologic pelvic effusion usually occurs around ovulation, follicular fluid accumulates in the pelvis during ovulation, usually the amount is relatively small, and the symptoms are relatively mild, just a slight abdominal pain during ovulation, and can be absorbed by itself, no need to do special treatment. Pathological pelvic effusion is mostly caused by gynecological diseases such as pelvic inflammatory disease, adnexitis, endometriosis and so on. It usually starts slowly from one side of the adnexal area and spreads to the opposite side, resulting in abdominal pain on one side and pain in the whole abdomen. It is also accompanied by abdominal distension, anal cramping sensation, and in severe cases, pain in the lumbosacral region and lumbago. Patients with pelvic effusion are advised to seek timely medical attention and follow up treatment as prescribed by the doctor.