The left posterior pain of the waist can be caused by several reasons: first, herpes zoster, in the early stage of herpes zoster can have pain on one side of the waist, often hidden pain or stabbing pain, after 1-2 weeks in the incubation period can have clusters of herpes, this time to early diagnosis and treatment to the dermatology department. Second, intercostal neuralgia, when one side of the lumbar intercostal nerve at the intercostal nerve travel has inflammation, can have one side of the lumbar pain, then to early investigation and diagnosis, early nerve nutrition and closure treatment. Third, rib diseases, when there is a tumor or metastasis in the ribs, there can be pain on one side of the back at the ribs, then we should check the CT and ECT of the ribs to diagnose. Fourth, dermatome neuritis, when there is chronic inflammation of the dermatome nerve on one side of the lumbar area, there can be pain on one side of the lumbar area, often a palm-sized pain, which can be hidden or radiating pain, which should be diagnosed by early examination and examination, and early nerve nutrition and physical therapy.