The vague pain in the left side of the abdomen in the third trimester of pregnancy should be a normal physiological phenomenon. Most of them are caused by the enlargement of the uterus due to the gradual growth of the fetus, which pulls the muscles of the pelvic floor and the surrounding ligaments, and do not require special treatment. With the gradual increase of pregnancy month, pregnant women will gradually appear more obvious small abdominal pain symptoms are normal, after appropriate rest symptoms will gradually ease. Therefore, pregnant women need to pay attention to moderate exercise, not strenuous exercise or overexertion, to avoid causing pre-miscarriage or premature birth and other situations. During pregnancy, you need to pay attention to rest and exercise in moderation, and at the same time, you need to pay attention to regular work and rest and avoid staying up too late. Occasional vague pain in the abdomen during exercise or fatigue, emotional excitement, etc. is a normal physiological phenomenon, as long as there is no vaginal bleeding, there is no need to worry.