Smoking is harmful to the body, including causing chronic respiratory diseases, malignant tumors, cardiovascular and cerebrovascular diseases, diabetes, etc. Anyone who smokes should avoid smoking and quit in time. Tobacco combustion will produce smoke containing nicotine, benzopyrene, tar and other harmful substances. These substances on the one hand will damage the mucous membrane epithelium of the airway and vascular endothelium, resulting in respiratory and circulatory diseases; on the other hand, nicotine and other carcinogens will also induce tumors. Smoking increases the risk of many diseases, such as chronic obstructive pulmonary disease, bronchial asthma, tuberculosis and other chronic respiratory diseases, lung cancer, laryngeal cancer, cervical cancer, bladder cancer, liver cancer and other malignant tumors, coronary heart disease, stroke, hypertension and other cardiovascular diseases, as well as diabetes. Smoking is harmful to health, and it is recommended to quit smoking in time.