Taurean fluid is often referred to as pelvic fluid in clinical practice. There are two types of fluid: physiological fluid and pathological fluid. Physiological effusion is the fluid that normally exists in the pelvic cavity, which lubricates the organs in the pelvis and prevents organ adhesions. There are many causes of pathological effusion, such as:a. Pelvic inflammatory disease. It is one of the most common diseases in which pelvic effusion occurs. The clinical manifestations are distension and pain in the abdomen, increased vaginal discharge and yellow color. Second, luteal crack. Most of the time, there is tearing pain on one side of the abdomen between menstruation, and there may be pressure pain and rebound pain on physical examination. pelvic fluid is seen on ultrasound. Most of this fluid is blood. Third, ectopic pregnancy rupture or miscarriage. Usually regular menstruation, delayed menstruation, regular sexual life, no contraception, severe pain in the small abdomen, and imaging examination shows large amount of pelvic fluid.