After 30 years of smoking, the addiction will be greater, lung function will decline, emphysema will form, and lung tumors will develop. Studies show that about thirty to ninety percent of smokers will have tobacco dependence. After 30 years of smoking, the addiction will be greater, and once you quit, the onset of nicotine dependence may intensify. It may also be accompanied by headaches, anxiety, and depression. The condition of the lungs is significantly different after 30 years of smoking, with a decline in lung function, emphysema formation, and the development of lung tumors, which can be assessed by CT and bronchoscopy. Second-hand smoke can also be harmful, and it is recommended to quit smoking as soon as possible to avoid health risks to the body.