38 weeks pregnant with a vague pain in the upper left abdomen, may be caused by improper diet, uterine enlargement, uterine fibroids, ovarian cysts or premature labor, etc., should go to the hospital to improve the blood tests, ultrasound, gynecological examination, etc., a clear diagnosis, some do not need special treatment, some should be as soon as possible with a professional doctor for medication, surgical treatment, etc.. 1. Improper diet: If you are 38 weeks pregnant and have an improper diet, such as eating unclean food, causing vague pain in the left upper abdomen, you can apply appropriate hot compresses or massage to relieve abdominal pain. 2. Enlargement of the uterus: If the uterus increases significantly during the 38th week of pregnancy, resulting in pressure on the stomach, causing vague pain in the upper left abdomen, you should eat small meals and change the position appropriately to avoid long-term compression of the stomach, which can relieve the pain. 3. Uterine fibroids: If you have uterine fibroids in the 38th week of pregnancy, causing vague pain in the left upper abdomen, it may be caused by degeneration of uterine fibroids, and should be treated with surgery as soon as possible. 4. Ovarian cysts: If you have ovarian cysts at 38 weeks of pregnancy, causing vague pain in the left upper abdomen, it may be caused by ovarian cysts with torsion, and you should cooperate with your doctor to take laparoscopic interventional surgery as soon as possible to remove them. 5. Pre-eclampsia: If you are 38 weeks pregnant and have a vague pain in your left upper abdomen, it may be a symptom caused by pre-eclampsia, when the fetus is already full-term, you can prepare for labor. If you are 38 weeks pregnant with a vague pain in the upper left abdomen, there may also be digestive diseases, it is recommended to go to a regular hospital obstetrics and gynecology department as soon as possible, timely exclusion of disease factors.