The causes of chest tightness, breathlessness and rapid heartbeat include physiologic factors, cardiogenic diseases, respiratory diseases, vegetative nerve dysfunction and hyperthyroidism. 1. Physiological factors: due to emotional excitement, strenuous exercise and other factors activate the sympathetic nerves, secretion of a large number of catecholamines, causing a rise in blood pressure, the heart rate will be accelerated, with a subsequent increase in the amount of output, resulting in chest tightness, breathlessness, rapid heartbeat. 2. Diseases of cardiac origin: including angina pectoris, myocardial infarction, myocarditis, chest tightness, breathlessness, rapid heartbeat, combined with electrocardiogram, cardiac ultrasound, dynamic electrocardiogram and other tests to diagnose, and in severe cases, may even be fatal. 3. Respiratory diseases: including lobar pneumonia, pneumothorax and so on. Lobar pneumonia is related to bacterial and viral infections, etc. At the onset, pleural involvement manifests as chest tightness, breathlessness, rapid heartbeat, accompanied by cough and fever. When sudden pneumothorax, it can be manifested as chest tightness, breathlessness, rapid heartbeat and other symptoms. 4. Phytoneurological dysfunction: prolonged excessive fatigue, undisciplined life, etc. can cause phytoneurological dysfunction, which may be manifested as chest tightness, breathlessness, rapid heartbeat and other symptoms at the onset. 5. Hyperthyroidism: hypermetabolism at the onset of the disease, manifested as chest tightness, breathlessness, rapid heartbeat, etc., combined with thyroid function and other tests to diagnose. If the patient’s prolonged chest tightness, breathlessness and rapid heartbeat do not improve, it is necessary to go to the hospital in time.