The reasons for chest tightness and shortness of breath when smoking more are as follows: 1. Smoking more, the chemical substances in tobacco can directly stimulate the bronchial tubes, causing them to spasm, and patients can therefore have symptoms of chest tightness and shortness of breath. 2. Smoking a lot for a long time can lead to the formation of slow branches and emphysema, and patients have chest tightness and shortness of breath due to a decline in lung function. Especially in emphysema patients, the symptoms of chest tightness can be significantly aggravated after activity, at which time it is necessary to improve lung function tests.3. Some patients can also suffer from coronary heart disease as a result of smoking more, which can lead to chest tightness and shortness of breath due to myocardial ischemia and cardiac arrhythmia.4. Some people who smoke for a long time and in large quantities can lead to pneumonia, lung cancer, interstitial lung disease and other conditions, and patients can therefore also experience varying degrees of chest tightness and Shortness of breath. Therefore, when smokers have chest tightness and shortness of breath, they need to go to the hospital to improve the relevant examination to clarify the causes and then carry out targeted treatment.