Back pain in the middle of pregnancy is mainly due to the fact that as the fetus grows and develops, the uterus gradually becomes bigger and the weight to be carried by the waist gradually increases, which results in the symptoms of back pain. This is a normal phenomenon during pregnancy and no special treatment is needed. Pregnant women should pay attention to rest and not overexert themselves. In addition, mid-pregnancy lumbago may also be due to calcium deficiency, lumbar muscle strain, urinary tract stones, pre-eclampsia, acute pyelonephritis and other abnormal conditions, need to identify treatment. 1, calcium deficiency: mid-pregnancy, with the growing fetus, the demand for calcium is increasing, if the pregnant woman calcium intake is not enough, may appear symptoms of lumbago. In this case, pregnant women should pay attention to timely supplementation of calcium substances, such as calcium supplements, eat foods with high calcium content, such as milk, eggs, shrimp, etc.; 2, lumbar muscle strain: some pregnant women in mid-pregnancy work or excessive activity, may appear lumbar muscle strain, resulting in the usual feeling of lumbar pain, pounding the waist to reduce the symptoms. In this case, it is recommended that pregnant women can use traditional Chinese medicine massage and physical therapy to relieve the discomfort. If the symptoms of lumbar soreness are more serious, it is recommended to visit the orthopedic department of the hospital and use medication under the guidance of the doctor. 3. urinary stones: pregnant women with urinary stones during pregnancy can also lead to lumbar soreness and pain, and the pain is mostly located in the lumbar ribs. In this case, it is recommended that pregnant women drink more water, and if the symptoms worsen, it is recommended to go to urology for treatment to avoid complications of kidney stones; 4. Pre-eclampsia: If a pregnant woman is stimulated by adverse factors, such as trauma, radiation, infection, etc., which cause contractions, she is prone to symptoms of lumbar acidity, suggesting that pre-eclampsia may have occurred, and it is recommended that pregnant women go to the hospital for fetal preservation treatment in a timely manner; 5. Acute pyelonephritis: the pathogen can be transmitted through upstream The pathogen can invade the renal pelvis through upstream infection, bloodstream infection and lymphatic tract infection, resulting in inflammation, leading to symptoms of lumbago in mid-pregnancy, usually accompanied by chills, fever, painful urination and frequent urination. It is recommended to actively seek medical attention and use antibiotics available for pregnant women to give treatment. Pregnant women should pay attention to rest in the middle of pregnancy and not to sit or stand for a long time to avoid damage to the joints of the waist and legs. In addition, pregnant women should pay attention to a balanced diet, timely replenishment of trace elements required by the body, to improve their physical quality.