The causes of chest blockage and breathlessness may include respiratory system diseases, cardiovascular system diseases, neurological changes and poisoning. 1. Respiratory system diseases: mainly respiratory system diseases lead to ventilation, ventilation dysfunction, causing hypoxia symptoms, such as pneumonia, bronchial asthma, pleural effusion, pneumothorax, airway foreign body. 2. Cardiovascular system diseases: heart failure can be seen in the heart pumping function decline, causing stasis in the pulmonary circulation, resulting in lung function gas exchange disorders, chest tightness symptoms, can also be seen in myocardial ischemia and other conditions 3. Mental illness: excessive anxiety, depression can cause patients to appear chest tightness symptoms. 4. Poisoning: caused by metabolic alkalosis, chemical poison, drug poisoning. Commonly, such as carbon monoxide poisoning, organophosphorus poisoning. Suddenly feel chest blockage can not come up to breathe continued unrelieved, please consult a doctor in time to avoid delay in treatment.