Abdominal distension, chest tightness and shortness of breath may be caused by mental factors, pulmonary insufficiency, cardiac insufficiency, gastritis, peptic ulcer and so on. 1. Psychological factors: nervousness, anxiety, depression, etc. can cause autonomic disorders, leading to circulatory, respiratory and digestive systems are affected, causing abdominal distension, chest tightness, shortness of breath. 2. Pulmonary insufficiency: such as emphysema, pulmonary hypertension, etc. affecting the right ventricle pumping function, gastrointestinal tract and systemic tissues blood reflux obstruction, can also cause abdominal distension, chest tightness, shortness of breath. 3. Cardiac insufficiency: when left ventricular dysfunction occurs, it will lead to blood circulation obstruction causing pulmonary stasis, thus causing abdominal distension, chest tightness and shortness of breath. 4. Gastritis: when there is inflammation of gastric mucosa, it can affect the digestion of food, resulting in the retention of food in the stomach and intestines, abdominal distension, compression of the chest cavity can cause chest tightness, shortness of breath, accompanied by acid reflux, nausea and other symptoms. 5. Peptic ulcer: such as duodenal ulcer can cause pyloric stenosis, or even obstruction, resulting in gastric contents can not be discharged, increased gastric pressure can cause abdominal distension, chest pressure can lead to chest tightness and shortness of breath. The causes of bloating, chest tightness and shortness of breath are many, so it is recommended to seek medical advice as soon as possible, identify the causes under the guidance of professional physicians and treat them as soon as possible.