The lungs of long-term smokers are brown and black, and the longer you smoke, the darker the color. Some smokers even have a lot of air bubbles in their lungs. Smoking kills the cilia in the lungs, which are hair-like substances that help filter out impurities and prevent infection. When the lungs are not protected by these natural cilia, the chemicals in cigarettes may remain in the lungs, increasing the risk of cancer or disease. Symptoms of lung damage from long-term smoking include shortness of breath, coughing and persistent chest infections. If any of these symptoms occur, patients are advised to go to a regular hospital for timely examination and consultation. Smokers are advised to quit smoking in time, which can reduce the symptoms and gradually show improvement. Diet is recommended to be light, avoiding greasy, spicy and irritating foods.