Back pain in the sixth month of pregnancy can be seen for a variety of reasons, it is recommended that pregnant women take appropriate rest and change poor sitting posture, which can generally improve the symptoms of back pain. Common clinical reasons are as follows: 1. Uterus enlargement: In the sixth month of pregnancy, the enlarged uterus protrudes forward so that the center of gravity of the torso shifts backward, the lumbar vertebrae protrude forward, the entire back muscle is under continuous tension, and pregnant women often experience slight back and lumbar pain. Try to put a pillow on the lumbar back when resting, which can relieve the symptoms of pain, bed rest and local hot compresses if necessary. If the back pain is obvious, it is recommended to go to orthopedics or pain department in time to find out the cause and treat the symptoms. 2. Hormonal changes: Due to the hormonal changes in pregnant women, it is easy to make the joint ligaments relax, which leads to the appearance of back pain symptoms. It is recommended that pregnant women should avoid sitting or standing for a long time to relieve the discomfort; 3, bad posture: for example, pregnant women have poor sitting posture, work for a long time with their hands in the absence of support points, such as typing on the computer for a long time, which causes back pain, and there is no direct correlation with pregnancy. In this case, it is recommended that pregnant women improve their poor posture, move properly and avoid being in the same posture for a long time; 4. Other: it may be related to the heart or lung lesions of pregnant women, such as myocardial ischemia and pneumonia. It is recommended that pregnant women go to the hospital for ECG and cardiac ultrasound to identify the cause and treat the cause. If there is no problem, you should pay attention to rest and avoid eating spicy food.