May 31st is World No Tobacco Day. The harm of tobacco is one of the most serious public health problems in the world. Smoking is the culprit of chronic respiratory diseases, cancer, cardiovascular and cerebrovascular diseases, diabetes and many other diseases. At the same time, second-hand smoke also does great harm to health. More than 1 million people in China lose their lives due to tobacco every year, "Ye Ling, deputy director of the Respiratory Department of the People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, said in an interview with People's Daily that smoking causes respiratory diseases. Smoking damages lung structure, lung function, and respiratory immune system function, causing various respiratory diseases. When tobacco is burned, it releases 38 toxic chemicals, such as tar, carbon monoxide, nicotine, dioxins, and irritating smoke. Tar can cause damage to the mouth, throat, trachea, and lungs. According to statistics, the proportion of smokers suffering from lung diseases after the age of 60 is 74%, while the proportion of non-smokers suffering from lung diseases after the age of 60 is only 4%. Smoking causes cardiovascular and cerebrovascular diseases. Smoking can damage the endothelial function of blood vessels, cause atherosclerosis changes, narrow the vascular lumen, block arterial blood flow, and cause a variety of cardiovascular and cerebrovascular diseases. Smoking can also affect other risk factors of cardiovascular and cerebrovascular diseases, producing synergy. There is sufficient evidence that smoking can lead to atherosclerosis, coronary atherosclerotic heart disease, stroke, and peripheral artery disease. The greater the amount of smoking, the longer the number of years of smoking, the higher the risk of disease onset. There is evidence to suggest that smoking can increase the risk of developing hypertension. Smoking causes cancer. Tobacco smoke contains at least 69 carcinogen. When human body is exposed to these carcinogen, carcinogen will cause permanent mutations in key genes in the body and gradually accumulate, and the normal growth regulation mechanism is out of balance, leading to the occurrence of malignant tumors. There is sufficient evidence that smoking can lead to lung cancer, laryngeal cancer, bladder cancer cancer, gastric cancer, cervical cancer, ovarian cancer, pancreatic cancer, liver cancer, esophageal cancer, kidney cancer, etc. The larger the amount of smoking, the longer the number of years of smoking, the higher the risk of disease. There is evidence that smoking can increase the risk of acute leukemia, nasopharyngeal cancer, colorectal cancer, and breast cancer. Smoking causes diabetes. Smoking increases the secretion of hormones that counteract insulin, affects the synthesis of insulin signaling proteins in cells, inhibits insulin production, and long-term smoking can also cause redistribution of adipose tissue, all of which can increase insulin resistance. There is sufficient evidence that smoking can lead to type 2 diabetes. The greater the amount of smoking, the younger the age of starting smoking, and the longer the number of years of smoking, the higher the risk of disease. Smoking can increase the risk of macrovascular and microvascular complications in diabetes. Quitting smoking can significantly reduce the risk of smoking related diseases and improve prognosis, "said Ye Ling. In recent years, China has achieved significant results in smoking control, with a significant decrease in smoking rates, but the number of smokers in China is still high. Although many people have realized the dangers of smoking, the painful process of quitting often leads many smokers to give up halfway. Although there may be some withdrawal symptoms after quitting smoking, they are the aftermath of the battle against smoking addiction. The withdrawal symptoms are strongest in the first 14 days of quitting smoking, and gradually decrease and disappear for about a month, "Ye Ling suggests. Ye Ling stated that