Causes of uterine fluid: 1, physiological phenomenon, occurring in women before menstruation or just after menstruation, the menstrual blood in the uterine cavity has not yet begun to drain or not completely drain, ultrasound examination of the uterine cavity there will be a separation of the phenomenon or the presence of intrauterine fluid, most women are no discomfort, no need to deal with the special beads, 3-5 days after the disappearance of their own. 2, gynecological inflammation caused by the most common is the uterine corpuscular and endometritis, due to the presence of inflammation, tissue exudate increased, manifested as uterine fluid and other accompanying symptoms, but also pressure and pain, pelvic pain. and endometritis, due to the presence of inflammation, tissue exudate increased, manifested as uterine fluid, but also the uterus pressure pain, pelvic fluid and other accompanying symptoms. Mainly through the application of antibiotic anti-inflammatory treatment can be relieved and disappear. 3, pelvic tumors, local tumors produce exudate caused by uterine effusion, through the ultrasound examination can be found in the local mass, this situation requires further examination to confirm the diagnosis and treatment.