Lumbar pain in the 30th week of pregnancy may be caused by overloading of lumbar vertebrae, overwork, urinary stones and so on. It can be relieved by localized hot compresses, bed rest, and drinking a lot of water to expel stones. 1. Lumbar spine load is too large: 30 weeks of pregnancy belongs to the late pregnancy, with the increase of the fetus, the center of gravity of the body shifted forward, the lumbar spine load is too large. At this time, you can relieve lumbar pain through localized hot compresses. 2. Overwork: 30 weeks pregnant, overwork will increase the burden on the waist. Lower back pain should be bed rest, lying flat or side lying can accordingly reduce the burden on the lumbar region, so that the lumbar pain can be relieved. 3. Urinary stones: when suffering from urinary stones, stone compression of the renal pelvis or ureter will cause severe pain, at this time, pregnant women are not suitable for Western medicine or surgical treatment, you can drink a lot of water to make the stones discharged. If the back pain cannot be relieved by local hot compresses and bed rest, she should consult a doctor in time to find out the cause, and should not take any unauthorized treatment, so as not to affect the safety of mother and child.