Smoking definitely has an effect on the lungs and can cause serious damage, as long as the duration of smoking is long enough and the amount of smoking is relatively large, such as 1 pack a day or 2 packs a day, it will cause abnormal lung CT performance. Early ultra-thin CT, may find bronchial wall thickening, that is, cigarettes cause bronchitis, may be found to have emphysema, pulmonary pneumonia, that is, lobar central type emphysema, pulmonary pneumonia, also cause interstitial fibrosis. Because the thickening of the bronchial wall causes interstitial lung changes, the changes later cause interstitial lung fibrosis. It may also cause nodules in the lungs and eventually lead to lung tumors. Because there is a relationship between lung tumors and smoking, smoking patients are prone to lung tumors. Therefore, the main abnormalities of lung CT in patients who smoke are bronchial wall thickening, emphysema, pulmonary maculopathy, interstitial fibrosis, including pulmonary nodules, and even cause lung cancer. Some patients who do not smoke will have emphysema, pulmonary blisters, and lung cancer present even if they do CT, but if they smoke, they must take it very seriously and must quit smoking and have further tests done to evaluate it, such as lung function, to test whether smoking has any effect on lung function. Usually the longer you smoke and the more you smoke, the more abnormal the CT of the lungs will definitely be.