Hidden pain in the left middle abdomen may be caused by stomach diseases, urinary system diseases, intestinal diseases and so on. 1. Gastric diseases: when the patient suffers from acute and chronic gastritis, gastroduodenal ulcer and other diseases, it will easily lead to gastric mucosal lesions, the symptoms of vague pain in the left abdomen. 2. Urological diseases: if the patient suffers from ureteral tuberculosis, left ureteral stone, left nephritis and other diseases, it will be easy to involve the surrounding abdominal tissues, resulting in the phenomenon of left mid-abdominal pain. 3. Intestinal diseases: if the patient has intestinal tuberculosis, ulcerative colitis, ischemic enteropathy and other diseases, it will easily lead to intestinal mucosal ulceration, erosion, hemorrhage and other lesions, resulting in vague pain in the left abdomen. When the patient has a vague pain in the left middle abdomen, it may also be suffering from other diseases, such as chronic pancreatitis. You should go to the hospital immediately to get a clear diagnosis and then follow the doctor’s instructions for active treatment.