Smoking in men can cause different degrees of damage to the lungs, heart, mouth and other parts of the body, inducing diseases. For the sake of health, it is recommended to quit smoking. 1. Lung respiratory diseases: smoking will make the carcinogenic substances in cigarettes through the nasal cavity, trachea, after a long time will change the function of the epithelium of the bronchial mucosa, resulting in bronchitis and other diseases. Sucked into the lung tissue also makes lung cells cancerous, causing malignant tumors. 2. Heart: carbon monoxide in the smoke will reduce the ability of blood red blood cells to carry oxygen, nicotine will make the heart beat faster, higher blood pressure, resulting in weakening the heart’s ability to withstand, myocardial hypoxia, prone to angina pectoris, acute myocardial infarction and other diseases to increase the risk of the incidence of disease. 3. Oral disease: smoking will make tartar deposits on the tooth surface, accelerate the formation of plaque on the tooth surface, leading to gingivitis and periodontitis and other periodontal diseases. It also causes white spots on the oral mucosa, which may develop into cancer. In addition, smokers will have tobacco stains deposited on the teeth to affect the aesthetic appearance of the teeth, the mouth will also have a bad taste leading to bad breath, and so on. To summarize, smoking is harmful to men and it is recommended to quit smoking as soon as possible to avoid health problems.