Pain on the left side of the belly, first of all, look at the surface of the belly for redness, hard nodes, blisters, if there are blisters, redness and swelling, it may be pain caused by herpes zoster, which is a viral infection, oral antiviral drugs can be taken. It may be caused by acute abdomen, commonly kidney stones, ureteral stones, intestinal adhesions, intestinal obstruction, etc. If it is kidney stones and ureteral stones, the pain generally lies in the left side of the waist, left lower abdomen, left side of the abdomen can appear pain, the nature is more intense, usually accompanied by nausea, vomiting and other gastrointestinal symptoms, blood can also be found in the urine, the examination needs to perform ultrasound, ultrasound can find that there are kidney or ureteral Ultrasound can detect stones in the kidney or ureter, and if stones are found, they need to be crushed or treated symptomatically for pain. If the pain is caused by intestinal adhesions or intestinal obstruction, there is a history of surgery in the abdomen, and adhesions may form between the intestines after surgery, and when the abdomen is cold or other causes of increased intestinal peristalsis, there may be a burst of pain in the abdomen. If the pain is chronic, it may be caused by colon tumor, the pain is mild and vague, and when the tumor causes obstruction, acute abdominal pain and paroxysmal abdominal pain may appear.