It may belong to normal physiological pain or pathological pain, such as pre-eclampsia, gastrointestinal disorders, etc., which need to be treated properly after clarifying the cause. 1, common causes 1, physiological pain: with the continuous growth and development of the fetus in the uterus, the uterine muscles and ligaments to bear more and more tension, coupled with the growing uterus continue to press the surrounding tissues and organs, these factors will lead to pregnant women feel the left side of the stomach hidden pain; 2, pathological pain: when pregnant women appear lower abdominal pain accompanied by vaginal bleeding, pay attention to the possibility of pre-eclampsia abortion. Some pregnant women have gastrointestinal disorders due to improper diet during pregnancy, which can also lead to diarrhea and abdominal pain. Some pregnant women have had surgery on their abdomen, causing intestinal obstruction due to adhesion between the wound and the intestine, which can also cause pain on the left side of the abdomen of pregnant women. Second, treatment 1, when pregnant women have left abdominal pain, if it is only mild or can be relieved by resting for a while during the attack and there is no bleeding symptom, it can be temporarily observed and does not need special treatment; 2, if the pain continues to increase and is accompanied by symptoms of vaginal bleeding, go to the hospital immediately to check whether there is a possibility of preterm abortion and carry out fetal preservation treatment for specific conditions. For non-obstetrical and gynecological diseases, symptomatic treatment by professional doctors combined with the specific conditions of pregnancy is needed. Third, precautions pregnant women should not panic when they have left abdominal pain, pay more attention to rest, balanced diet, do not eat cold food, moderate exercise, do not engage in heavy labor, do not stay up late, keep a happy mood, safely through the pregnancy.