The hidden pain in chest when swallowing food may be caused by esophagitis, pneumothorax and esophageal cancer. 1. Esophagitis: when patients with esophagitis swallow food, there is obvious pain behind the sternum and accompanied by difficulty in swallowing; in serious cases, the esophagus becomes narrow, and even nausea and vomiting occur, which makes the patients feel vague pain in the chest when swallowing food. 2. Pneumothorax: Pneumothorax is related to the respiratory tract and esophagus, and some of the muscles of pneumothorax will be pulled when swallowing food, so the vague pain in chest when eating may be a symptom of pneumothorax. 3. Esophageal cancer: the clinical characteristic of esophageal cancer is progressive dysphagia, and some types of esophageal cancer will lead to narrowing of esophagus, which will lead to blockage and vague pain in chest when swallowing food. When patients feel vague pain in chest when swallowing food, they should go to the hospital for relevant examination in time, and clarify the cause of the disease and treatment under the guidance of doctors.