Although most people know that smoking is harmful to health, they do not have sufficient knowledge of the highly addictive nature of smoking, the diversity of harms and the seriousness of the problem, so that the number of smokers in our country remains high. At present, on the issue of tobacco, our country set “three of the most” in one: the largest tobacco producer, cigarette production and sales account for about 40% of the world; the largest consumer of tobacco, the number of smokers in our country more than 300 million, the male smoking rate of more than 50%, in addition, there are more than 700 million non-smoking people suffered from second-hand smoke; the largest tobacco victim country! The number of deaths caused by smoking-related diseases in China exceeds 1 million per year. If the smoking situation is not controlled, it is expected that by the middle of this century, the number of deaths caused by smoking-related diseases is expected to exceed 3 million. 1. Harmful substances contained in tobacco: China’s tobacco consumption is mainly smoking cigarettes, and the burning of tobacco can produce gas and smoke, known as tobacco smoke. Smokers in addition to their own inhalation of tobacco smoke, not inhaled and exhaled tobacco smoke can be spread into the air, the formation of “second-hand smoke”. The chemical composition of tobacco smoke is complex, and hundreds of substances have been found to pose health risks. Harmful substances include at least 60 kinds of known carcinogens, such as aromatic hydrocarbons, N-nitrosamines, aromatic amines and formaldehyde, etc. Tobacco combustion can also produce such as carbon monoxide (CO), nitric oxide (NO), hydrogen sulfide (H2S) and other harmful gases, which can be harmful to the respiratory system, and the tobacco also contains nicotine, which is highly addictive. “Tar” is the product of incomplete combustion of organic matter in tobacco, containing a variety of hydrocarbons and hydrocarbon oxides, sulfides and nitrides. Tobacco companies have introduced “low-tar cigarettes” and “herbal cigarettes”, as well as the use of small box packaging to promote consumption, but these tobacco products do not reduce the health hazards of smoking, but rather induce smoking and influence smokers to quit. 2. Smoking and Disease 1) Tobacco Dependence Smoking can be addictive and is called tobacco dependence, which is an important reason why smokers smoke for a long time and find it difficult to quit. The main substance in tobacco that causes addiction is nicotine, so tobacco dependence is also called nicotine dependence. Tobacco dependence is actually a disease, and many people who smoke have varying degrees of tobacco dependence. After a tobacco dependent person stops smoking for a period of time, he or she can experience a series of withdrawal symptoms such as smoking cravings, anxiety, depression, dizziness, headaches, salivation, etc., and as a result, he or she will pursue smoking again. In fact, many smokers do not seek the pleasure of smoking, but rather smoke to relieve withdrawal symptoms such as anxiety and dizziness. 2) Smoking and Cancer It is now known that tobacco smoke contains more than 60 carcinogens, which can trigger gene mutations in the human body, leading to dysfunction of the normal growth control mechanism, and ultimately leading to the activation of cancer genes and the development of malignant tumors. There is sufficient evidence that smoking can lead to lung cancer, oral and nasopharyngeal malignant tumors, laryngeal cancer, esophageal cancer, gastric cancer, liver cancer, pancreatic cancer, renal cancer, bladder cancer, and cervical cancer, and smoking cessation can significantly reduce the risk of these cancers. In addition, evidence suggests that smoking can also lead to colorectal cancer, breast cancer and acute leukemia. 3) Smoking and Respiratory DiseasesCigarette smoke has an impact on the immune function of the respiratory tract, the structure of lung tissue and lung function, causing a variety of respiratory diseases: smoking can lead to chronic obstructive pulmonary disease (referred to as chronic obstructive pulmonary disease) and asthma in adolescents, and smoking can also increase the risk of tuberculosis and other respiratory infections. 4) Smoking and Cardiovascular DiseasesSmoking damages the endothelial function of blood vessels and can lead to the development of atherosclerosis, which narrows the arterial blood vessels and leads to a variety of cardiovascular and cerebrovascular diseases, such as coronary heart disease, stroke and peripheral arterial disease. 5) Smoking and reproductive and developmental abnormalities Tobacco smoke contains a variety of harmful substances that can affect human reproductive and developmental functions. Smoking damages genetic material and has harmful effects on the endocrine system, fallopian tube function, placental function, immune function, cardiovascular system of pregnant women and fetuses, and the development of fetal tissues and organs. Smoking reduces the chances of conception, increases the risk of ectopic pregnancy and spontaneous abortion, and can lead to placenta previa, placental abruption, fetal growth restriction, low birth weight, and sudden infant death syndrome (SIDS). In addition, evidence suggests that smoking can also lead to erectile dysfunction in men. 6) Smoking and Diabetes There is evidence that smoking can cause type 2 diabetes and can increase the risk of macrovascular and microvascular complications in people with diabetes, affecting the prognosis of the disease. 7) Smoking and Other Health Problems There is strong evidence that smoking can lead to periodontitis, cataracts, and that smoking in people with Helicobacter pylori infection can lead to peptic ulcers. In addition, there is evidence that smoking can also lead to dementia. 3, the health risks of secondhand smoke Secondhand smoke contains a large number of harmful substances and carcinogens, non-smokers inhale secondhand smoke, will also increase the risk of a variety of smoking-related diseases. Secondhand smoke can also lead to lung cancer, nasal irritation and coronary heart disease. In addition, secondhand smoke can lead to breast cancer, bronchial asthma, chronic obstructive pulmonary disease, stroke and atherosclerosis. Exposure to secondhand smoke is particularly harmful to the health of pregnant women and children. Inhalation of secondhand smoke by pregnant women can lead to sudden infant death syndrome (SIDS) and low birth weight of the fetus. In addition, exposure to secondhand smoke can lead to preterm labor, neural tube defects in newborns, and cleft lip and palate. In children, exposure to secondhand smoke increases the risk of respiratory infections and can lead to bronchial asthma, decreased lung function, acute otitis media, recurrent otitis media, and chronic middle ear effusion. In addition, children exposed to secondhand smoke can also lead to a variety of childhood cancers, exacerbate the condition of children with asthma, and affect the effectiveness of asthma treatment. 4, the benefits of quitting smoking Through the above explanation, we have understood the serious harm caused by smoking to human health, and quit smoking is the only way to reduce the occurrence of smoking-related diseases, reduce the harm of smoking. Smokers who quit smoking experience significant health benefits, including increased longevity, reduced risk of morbidity and mortality from smoking-related diseases, and improved prognosis for many smoking-related diseases. Reducing the amount of cigarettes smoked does not reduce the risk of morbidity and mortality among smokers. Quitting smoking at any age can be beneficial. Therefore, it is better for smokers to quit than not to quit, and it is better to quit earlier than later. It is believed that many smokers will be willing to quit after fully understanding the health risks of smoking and the benefits of quitting. For non-addicted or less addicted smokers, it is possible to quit with perseverance, but it is often necessary to give strong advice and encouragement to stimulate the motivation to quit; for those with a high degree of tobacco dependence, it is often necessary to give stronger cessation treatments to finally succeed in quitting smoking. First-line smoking cessation medications currently used include nicotine replacement preparations such as bupropion and farnesylate. Tobacco cessation clinics are an effective way to provide intensive treatment for tobacco-dependent smokers, and most tertiary care hospitals now have tobacco cessation clinics that smokers with severe tobacco dependence can go to if they fail to quit on their own.