Abdominal pain is the pain that occurs in the abdomen of the body from the lower edge of the rib cage to the pubic bone. The specific location of abdominal pain varies, as do the corresponding diseases. According to where the abdominal organs are located, they are divided into upper left, lower left, upper right and lower right, centered on the umbilicus. Therefore, according to the location of the pain, it is divided into upper left abdominal pain, lower left abdominal pain, upper right abdominal pain and lower right abdominal pain. There are various causes of left upper abdominal pain, the common ones are gastritis (which may be related to eating and may be accompanied by nausea, vomiting, acid reflux and burning sensation in the stomach), peripleural inflammation, pancreatitis (often patients have alcohol consumption or overeating), splenic flexure colon tumor, intercostal neuralgia and costochondritis. There are also a few patients with acute myocardial infarction who can present with left upper abdominal pain accompanied by nausea and vomiting, but acute myocardial infarction often has a history of angina attack, characteristic manifestations of electrocardiogram and abnormal laboratory tests, accompanied by chest tightness and profuse sweating. The cause of the left upper abdominal pain should also be noted along with its aggravating and relieving factors, as well as the duration and nature of the abdominal pain or the presence of other accompanying symptoms. All these can help in the diagnosis of abdominal pain and the clarification of its etiology. Therefore, left upper abdominal pain is one of the common clinical symptoms and should not be taken lightly even if it is episodic, especially in middle-aged and elderly people. When abdominal pain occurs, it is important to seek early medical attention to identify the cause and to receive appropriate treatment for the condition.