Clinically, there are still many causes of pain in the left posterior side of the waist, for the common consideration of the following causes: first, due to simple lumbar muscle strain, or sprain of the lumbar muscle, it will cause pain symptoms in the left posterior side of the waist. Second, patients with kidney problems, such as kidney stones, kidney tuberculosis, kidney tumors, will also cause pain symptoms on the left posterior side of the waist. Third, women with gynecological inflammation may also cause painful symptoms on the left posterior side of the waist. Fourth, intestinal lesions, such as tumors in the intestine, may also cause the left posterior side of the waist to have involvement pain. Therefore, there are many clinical causes of pain on the left posterior side of the waist, and the specific causes need to be clearly diagnosed according to the specific location of the same pain, the nature of the pain, the duration of the pain and combined with auxiliary examinations, and then active symptomatic treatment can be.