The time to start spitting up after quitting smoking varies from person to person, with early spitting up starting in about a week and late spitting up starting six months later. Because nicotine withdrawal syndrome occurs after quitting smoking, a number of symptoms can occur, including spitting up. Spitting up is due to long-term smoking, which leaves a large amount of tar and dust and other substances in the lungs. At this time, it will continuously mix with the secretions secreted by the glands in the respiratory tract, and through the cilia in the respiratory tract wall of the lungs, they will continuously push upwards and push out these substances until they are discharged from the airway, which is a normal phenomenon that occurs after quitting smoking.