The pain on the left side of the waist can be caused by the following reasons: first, kidney disease, when the kidneys have stones or tumors, cysts, there can be pain in the kidney area of one side of the waist, often soreness or swelling, can be accompanied by symptoms of hematuria and proteinuria, this time to check the ultrasound of the kidneys, CT and urine tests to diagnose and early treatment. Second, lumbar muscle strain, when one side of the lumbar muscles have chronic injury, there can also be a side of the lumbar pain, then early examination and examination to exclude other diseases to diagnose. Third, herpes zoster, in the early stage of herpes zoster can have hidden pain or stabbing pain on one side of the waist, after the incubation period can have herpes, then to the dermatology department for diagnosis and treatment. Fourth, intercostal neuralgia, patients with intercostal neuralgia can also have pain in one side of the lumbar intercostal nerve, often radiating pain or stabbing pain, which should be diagnosed by early physical examination, early nerve nutrition therapy and closure therapy. Fifth, dermatomal neuritis, when the dermatomal nerve in the lumbar region has chronic inflammation, there can also be hidden pain or stabbing pain on one side of the lumbar region, which should be investigated early and treated with nerve nutrition and physical therapy early.