Middle chest distention may be caused by gastritis, gastroesophageal reflux disease, bronchial asthma, and myocardial ischemia. The stomach is located above the left quarter rib area of the body, about where the chest is, and the lining of the stomach can become acutely or chronically inflamed due to irritation and invasion. Stomach discomfort can occur between meals or at night, with a strong burning sensation in the stomach before eating as well as a feeling of chest distention, which in a large percentage of people is manifested only as chest distention. Acid reflux disease is caused by the reflux of stomach acid to the connection between the cardia of the stomach and the esophagus, which is located approximately at the chest, and patients will experience severe heartburn, chest distension, and chest pain in the chest after eating. Patients with bronchial asthma, especially those with chest asthma, can present with only chest distention, which usually occurs at night or in the early morning and can also occur after exposure to allergens. Myocardial ischemia is due to insufficient blood supply to the heart muscle, which can reduce the ability of the heart muscle to pump blood, thus reflecting symptoms of chest distension, chest pain, rapid heartbeat, as well as nausea and vomiting, resulting in middle chest distension, which can also be determined by a timely visit to the hospital for further examination.