Hidden pain in the left upper abdomen against the ribs may be related to gastrointestinal diseases, costochondritis, pleurisy and other diseases. 1. Gastrointestinal diseases: such as gastric ulcer, gastritis, etc., can cause pain and discomfort in the left upper abdomen near the ribs, usually accompanied by belching, acid reflux and other gastrointestinal symptoms. 2. Costal chondritis: left-sided costal chondritis can cause pain in the left upper abdomen near the arch of the rib cage, mainly due to acute and chronic injuries caused by aseptic inflammation, usually manifested as deep breathing or lying on the left side of the pain aggravated. 3. Pleurisy: left pleurisy can lead to hidden pain in the left epigastric region near the ribs, the main symptom is fever, which can be accompanied by coughing, coughing up sputum, even when the pain is severe, there is a limitation of deep breathing. There are many other causes of pain in the left upper abdomen against the ribs, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, under the guidance of a doctor to determine the cause of the disease and targeted treatment, do not take medication, so as not to delay the condition.