The reasons for feeling chest tightness, shortness of breath and dyspnea from smoking are as follows: 1. Chemical stimulation: Patients can be stimulated by the chemical substances in the smoke when smoking, causing bronchospasm, and patients therefore have symptoms of chest tightness, shortness of breath and dyspnea, especially bronchial asthma patients can be induced by smoking to have an asthma attack, resulting in shortness of breath, chest tightness and other discomforts. 2. Lung disease: Patients who have smoked for a long period of time due to This is because of the fact that smoking is a major cause of asthma attacks, which can lead to shortness of breath and dyspnea. 3, heart disease: smoking can also cause coronary heart disease, myocardial ischemia and other conditions, which can lead to chest tightness, shortness of breath and dyspnea. So people must quit smoking early to avoid the discomfort caused by smoking related to heart and lung diseases.