Flatulence in the middle of the chest may be gastrointestinal diseases, respiratory diseases, cardiac system diseases and so on. 1. Gastrointestinal diseases: they may be related to flatulence, which is easily caused when eating spicy and irritating foods or foods that are easy to cause flatulence, thus leading to the feeling of chest tightness. It may also be pathological diseases, such as reflux esophagitis and gastritis, which often manifest as abdominal pain, bloating, belching, nausea and loss of appetite. Esophageal cancer can also cause chest swelling when there is difficulty in swallowing. 2. Respiratory system diseases: such as bronchial asthma patients, it can be manifested as swelling in the middle of chest, which usually occurs at night or in the early morning, or after contacting allergens. 3. Cardiac system diseases: such as myocardial ischemia, due to insufficient blood supply to the myocardium, the heart’s pumping ability decreases, thus reflecting symptoms such as chest tightness, chest pain, rapid heartbeat, nausea and vomiting. After the symptoms of swelling in the middle of the chest, it is recommended to go to the hospital in time for examination, to clarify the cause of chest tightness, and to be treated under the guidance of the doctor, so as not to delay the condition.