The vague pain on the left side of the uterus is considered to be left lower abdominal pain. In addition to diseases such as ruptured corpus luteum, pelvic inflammatory disease, ectopic pregnancy, ovarian cysts, endometriosis, etc., it may also be caused by other diseases, such as some intestinal as well as urinary system diseases. Patients need to combine other specific symptoms to clarify the cause. 1, rupture of corpus luteum: due to trauma, sexual intercourse and other reasons, the patient’s corpus luteum ruptured, at this time some patients can show a sudden and mild pain on the left side of the lower abdomen; 2, pelvic inflammatory disease: belongs to the infectious disease, generally manifested as chronic lower abdominal pain, sometimes manifested as vague pain on the left side of the uterus. The examination of the adnexal area thickening, pressure pain, uterine pressure pain is the specific signs of pelvic inflammatory disease, B ultrasound generally no special performance. The treatment should be antibiotics and anti-infection as prescribed by the doctor, and also combined with herbal medicines to invigorate blood circulation and remove blood stasis; 3. Ectopic pregnancy: if a woman has sex, she should go to the hospital to check blood and urine HCG to exclude the possibility of ectopic pregnancy. If the gestational sac is in the left fallopian tube and rupture has not occurred, the symptoms of vague pain on the left side of the uterus may occur, which requires timely treatment; 4. ovarian cysts: ultrasound examination should be done. If the ultrasound suggests the possibility of twisting of the left ovarian cyst, it will be accompanied by pain on the left side of the uterus, which usually has indications for surgical treatment; 5. endometriosis: the presence of painful nodules in the posterior vaginal fornix or the uterosacral ligament area on physical examination It is a specific sign of endometriosis, sometimes also manifested as vague pain on the left side of the uterus, which should be given specific treatment; 6. Other diseases: some intestinal and urinary system diseases can cause patients to have left lower abdominal pain, such as intestinal cramps, intestinal obstruction and urinary stones are common. Patients need medication or surgery under the guidance of doctors to relieve the pain.