The possible causes of left-sided lumbar pain symptoms in pregnant women include: I. Incorrect posture of pregnant women when standing, walking or sitting, which puts excessive pressure on the muscles of the left lumbar back, leading to chronic muscle strain and causing pain. Second, left hydronephrosis, kidney stones, pregnancy accompanied by left-sided kidney stones, due to the stones, resulting in urine in the kidney can not be discharged in time, causing hydronephrosis, which causes pain in the left side of the back. Third, after pregnancy, women become lazy, rest in bed for a long time, lack of necessary physical activities, so that chronic strain on the muscles of the lower back, causing symptoms of lumbar pain. Pregnant women need to pay attention in their daily life and try to maintain the correct posture when standing, walking or sitting. Pay attention to the combination of work and rest, and do not take long bed rest.