Lower back pain during pregnancy may be caused by urinary tract diseases, muscle strain, weight shift or bad posture, etc. The details are as follows: 1. Urological diseases: during pregnancy, if there are pyelonephritis, kidney stones and so on will cause back pain, you can go to the hospital to do ultrasound examination to clarify the cause of the disease, and follow the doctor’s instructions for treatment. 2. Muscle strain: During pregnancy, overwork or pressure on the fetus can lead to muscle strain in the lower back. When the muscle is strained, it will cause damage to the nerves in the lower back, resulting in lower back pain or limited movement. This can be relieved by rest or massage. 3. Center of gravity shift: As the fetus gradually increases in size, the load on the body will increase, causing the center of gravity of the body to shift. When the center of gravity is shifted, the strength borne by the waist will be continuously strained, which will easily induce low back pain. This is a normal phenomenon, usually can pay attention to rest, do not stand too much, relieve the phenomenon of back pain. 4. bad posture: sleeping on the side for a long time, it will lead to the lumbar bearing force in a tense state, will cause the lumbar pressure, so the phenomenon of back pain during pregnancy. You can adjust the posture or massage the waist and other ways to relieve, pay attention to massage strength should not be too heavy. It is recommended to pay attention to rest in general, do not have stress, and relax your mind. When back pain occurs during pregnancy, you should go to the hospital in time to identify the cause and then targeted treatment.