Tightness and pressure in the middle of the chest may be related to digestive system diseases, circulatory system diseases, respiratory system diseases and so on. 1. Digestive system diseases: such as reflux esophagitis, due to acid and alkali reflux leading to esophageal mucosal damage, its typical symptoms of acid reflux, heartburn, can be accompanied by chest tightness, chest pain and other symptoms. 2. Circulatory system diseases: such as coronary heart disease, coronary artery stenosis or occlusion, when the acute attack, due to myocardial ischemia, can appear in the precordial region of the squeezing pain, tightness in the chest, and can be involved in the middle of the chest. 3. Respiratory diseases: such as tension pneumothorax, due to the increase of pressure in the pleural cavity, it can affect the lungs to breathe, so that the middle of the chest appears to have a sense of compression. Tightness and pressure in the middle of the chest can also be seen in other diseases, it is recommended that patients go to the regular hospital in time to avoid delaying the condition.