The left side of men’s stomach may be due to improper diet, but also due to gastritis, enteritis, nephritis and other diseases. 1. Improper diet: If you don’t pay attention to your diet and consume spicy and irritating food, it may stimulate the gastric mucosa, which may cause pain on the left side of the stomach. 2. Gastritis: Gastritis is an inflammation of the gastric mucosa caused by various reasons, and the typical symptoms are pain in the middle and upper abdomen, abdominal distension and so on. If a man suffers from gastritis, there will be a hidden pain on the left side of the stomach. Its causes are related to stress, drugs, alcohol and Helicobacter pylori infection. 3. Enteritis: enteritis is caused by bacterial, viral, fungal and other pathogen infections, and the typical symptoms of patients are abdominal pain, diarrhea, bloody stools and so on. If you are suffering from enteritis, it will also lead to hidden pain on the left side of your stomach. 4. Nephritis: the cause of nephritis is not yet clear, may be related to viruses, bacterial infections, may also be drugs, autoimmune disorders or hereditary, the patient will have pain in the kidney area, if the left side of the kidneys suffer from inflammation, will lead to the left side of the tummy hidden pain. There are more reasons for the hidden pain on the left side of the stomach in men, and it is recommended that patients seek medical examination for a clear diagnosis.