China is a major producer and consumer of tobacco, and the annual consumption of tobacco accounts for more than 1/3 of the world’s total sales, with up to 300 million smokers. According to the Chinese Academy of Preventive Medicine estimates, about 400 million people are also harmed by passive smoking, so about 700 million people in China are directly or indirectly harmed by tobacco. Smoking can induce a variety of cancer, cardiovascular and cerebrovascular diseases, respiratory and digestive diseases, etc., and is one of the biggest causes of premature death and disability. A 40-year study in the United Kingdom proved that the mortality rate of middle-aged smokers is three times that of non-smokers, and WHO data show that currently 3 million people die each year from various smoking-related diseases worldwide, and it is estimated that by 2025 the number will rise to 10 million, while China will account for 2 million. Smoking has become an urgent problem that seriously endangers the health of our people. First, the impact on the heart and cerebrovascular Many studies have concluded that smoking is a major risk factor for many cardiovascular and cerebrovascular diseases, the incidence of coronary heart disease, hypertension, cerebrovascular disease and peripheral vascular disease are significantly higher in smokers. Statistics show that 75% of patients with coronary heart disease and hypertension have a history of smoking. The incidence of coronary heart disease is 3.5 times higher in smokers than in nonsmokers, the death rate of coronary heart disease is 6 times higher in the former than in the latter, and the incidence of myocardial infarction is 2-6 times higher in the former than in the latter, and pathological autopsy also reveals that coronary atherosclerotic lesions are more extensive and severe in the former than in the latter. The incidence of coronary heart disease was 9 to 12 times higher in those with hypertension, high cholesterol and smoking. Smoking is responsible for 30% to 40% of cardiovascular deaths, and the increase in mortality is proportional to the amount of smoking. Nicotine and carbon monoxide in cigarette smoke are recognized as the main harmful factors causing coronary atherosclerosis, but their exact mechanism is not fully understood. Most scholars believe that lipid changes, platelet function and blood rheology abnormalities play an important role. Smoking can damage vascular endothelial cells, causing peripheral vascular and coronary artery constriction, wall thickening, lumen narrowing and blood flow slowdown, resulting in myocardial hypoxia. Nicotine can also promote platelet aggregation. Carbon monoxide in cigarette smoke combines with hemoglobin to form carboxyhemoglobin, which affects the oxygen-carrying capacity of red blood cells and causes tissue hypoxia, thus inducing coronary artery spasm. As a result of tissue hypoxia, compensatory erythrocytosis is caused, which increases blood viscosity. In addition, smoking can increase plasma fibrinogen levels, leading to coagulation system dysfunction; smoking can also affect the metabolism of arachidonic acid, which leads to vasoconstriction and increased platelet aggregation. All of these may promote the occurrence and development of coronary heart disease. Because of myocardial hypoxia, smokers with coronary artery disease are more likely to have arrhythmias and have an increased risk of sudden death. It has been reported that the risk of stroke in smokers is 2 to 3.5 times higher than in nonsmokers; if smoking and hypertension coexist, the risk of stroke increases nearly 20 times. In addition, smokers are susceptible to occlusive arteriosclerosis and occlusive thromboarteritis. Smoking can cause chronic obstructive pulmonary disease (COPD for short), which eventually leads to pulmonary heart disease. Second, the impact on the respiratory tract Smoking is one of the main causes of chronic bronchitis, emphysema and chronic airway obstruction. Experimental studies have found that long-term smoking can damage and shorten the cilia of the bronchial mucosa and affect the clearance function of the cilia. In addition, the submucosal glands are enlarged and hypertrophied, and the mucus secretion is increased and the composition is changed, which can easily obstruct the fine bronchial tubes. According to reports, nearly 13 million people in the United States suffered from COPD in 1986 and more than 90,000 died in 1991, with smoking being its main cause. Chronic bronchitis is two to four times higher in smokers than in nonsmokers, and is proportional to the amount and years of smoking, and patients often have chronic cough, sputum and dyspnea during activity. Pulmonary function tests show airway obstruction, reduced pulmonary compliance, ventilation and diffusion function and decreased arterial partial pressure of oxygen. COPD predisposes to spontaneous pneumothorax. Smokers often suffer from chronic pharyngitis and vocal fold inflammation. Cigarette smoke, 92% for the gas, such as carbon monoxide, hydrocyanic acid and ammonia; 8% for particulate matter, these particles are collectively known as tar, containing nicotine, polycyclic aromatic hydroxyl, benzo(a)pyrene and β-naphthylamine, etc., has been confirmed to cause more than 40 kinds of carcinogens. The harmful effects of smoking on the human body are a slow process that takes a long time to show, and nicotine has an addictive effect, making it difficult for smokers to recognize. It is well established that smoking causes cancer. Epidemiological surveys have shown that smoking is an important causative factor for lung cancer, especially squamous epithelial cell carcinoma and small cell undifferentiated carcinoma. The risk of lung cancer in smokers is 13 times higher than that in nonsmokers, and 45 times higher than that in nonsmokers if they smoke more than 35 cigarettes per day. The mortality rate of lung cancer among smokers is 10-13 times higher than that of nonsmokers. About 85% of lung cancer deaths are caused by smoking. Smokers who are also exposed to chemical carcinogens (such as asbestos, nickel, uranium, and arsenic) have a higher risk of developing lung cancer. Smoking reduces the activity of natural killer cells, thus weakening the body’s ability to monitor, kill and remove tumor cell growth, which further explains why smoking is a high risk factor for the development of many cancers. The incidence of laryngeal cancer is more than ten times higher in smokers than in nonsmokers. There is a 3-fold increase in the incidence of bladder cancer, which may be related to the beta-naphthylamine in smoke. In addition, smoking is associated with the occurrence of lip, tongue, oral cavity, esophagus, stomach, colon, pancreatic, kidney, and cervical cancers. Clinical studies and animal experiments have shown that the carcinogenic substances in smoke can also affect the fetus through the placenta, resulting in a significantly higher incidence of cancer in its offspring. Third, the impact on the digestive tract Smoking can cause an increase in gastric acid secretion, generally 91.5% more than non-smokers, and can inhibit the pancreatic secretion of sodium bicarbonate, resulting in increased acid load in the duodenum, inducing ulcers. Tobacco nicotine can reduce the tone of the pyloric sphincter, making it easy for bile to reflux, thus weakening the defense factors of the stomach and duodenal mucosa, prompting chronic inflammation and ulcers, and delaying the healing of existing ulcers. In addition, smoking can reduce the tone of the lower esophageal sphincter, which can easily cause reflux esophagitis. Fourth, other smoking is more harmful to women than to men, smoking women can cause menstrual disorders, conception difficulties, ectopic pregnancy, low estrogen, osteoporosis and early menopause. Pregnant women who smoke are prone to spontaneous abortion, fetal growth retardation, and low birth weight. Other conditions such as preterm labor, stillbirth, early placental abruption, and placenta praevia may be associated with smoking. Smoking during pregnancy can increase fetal mortality before and after birth and the incidence of congenital heart disease. These hazards are due to carbon monoxide and other harmful substances in smoke entering the blood of the fetus, forming carboxyhemoglobin and causing hypoxia; at the same time, nicotine constricts blood vessels, reducing the blood supply and nutrient supply to the fetus, thus affecting the normal growth and development of the fetus. In women, 90% of lung cancers, 75% of COPD and 25% of coronary heart disease are related to smoking. The rate of death from breast cancer is 25% higher in women who smoke than in non-smoking women. Nicotine has been shown to lower sex hormone production and kill sperm, reducing sperm count, morphological abnormalities and viability, resulting in reduced chances of conception. Smoking can also cause damage to testicular function, male hypogonadism and sexual dysfunction, leading to male infertility. Smoking can cause tobacco amblyopia, and smoking in the elderly can cause macular degeneration, which may be due to atherosclerosis and an increased rate of platelet aggregation, contributing to local hypoxia. Recently, a study in the United States found that smoking in strong noise can cause permanent hearing loss, and even deafness. V. Passive smoking According to the definition of the World Health Organization, passive smoking refers to non-smokers who inhale smoke exhaled by smokers for more than 15 minutes/day on more than one day of the week. That is, people who live and work around smokers, unconsciously inhale smoke dust particles and various toxic substances. The concentration of harmful substances inhaled by passive smokers is not lower than that of smokers, and the cold smoke exhaled by smokers contains one times more tar, two times more benzopyrene, and four times more carbon monoxide than the hot smoke inhaled by smokers. In fact, an average of 1 hour of passive smoking per day is enough to destroy the arterial blood vessels. The results of a national test of 128 preschool children’s intelligence showed that passive smoking has a significant effect on children’s intelligence. Passive smoking can lead to addiction to nicotine, leading to active smoking in children and adolescents, and typical withdrawal symptoms upon cessation. Studies have found that women who are regular passive smokers in the workplace have a higher incidence of coronary heart disease than those who have no or little passive smoking in the workplace. The situation is even more worrisome for children, as passive exposure to environmental smoke has been implicated as a cause of respiratory disease, middle ear disease, asthma attacks, and sudden infant death syndrome. Sixth, quit smoking In summary, it is clear that smoking is very harmful to human health, and after quitting, its toxic effects will gradually decrease, most lesions can be reversed to varying degrees, and help reduce the incidence of COPD, coronary heart disease and cancer and mortality. This shows the importance of smoking cessation. Health education should strengthen the publicity and education on the harmful effects of smoking, prohibit smoking in public places, restrict advertising for tobacco companies, and print the “smoking is harmful to health” logo on cigarette boxes. There are many ways to quit smoking, such as acupuncture to quit smoking, quit smoking candy and quit smoking tea, but the main psychological victory, smokers really realize the danger of smoking, will be determined to quit early.