Hidden pain in the left upper abdomen after splenectomy may be caused by fluid accumulation in the splenic region, intestinal adhesion, wound infection and so on. 1. Fluid accumulation in the splenic region: If the connective tissue fluid near the splenic region is ruptured by external force or other inflammatory stimulation, fluid accumulation in the splenic region may also occur, resulting in vague pain in the left upper abdomen. 2. Intestinal adhesion: because splenectomy may lead to intra-abdominal inflammatory exudation, it is easy to develop intestinal adhesion and other complications, when the patient’s intestinal peristalsis will lead to vague pain in the left upper abdomen, and when the situation is serious, intestinal obstruction may also occur. 3. Wound infection: If the patient has improper postoperative care or improper medication change, bacteria and viruses may invade the body, resulting in wound infection, which may cause vague pain in the upper left abdomen. It is recommended that patients should go to the hospital immediately when they feel unwell, identify the cause of the disease and follow the doctor’s instructions to deal with it accordingly, so as to avoid delaying the condition.