There is no specific time limit for starting detoxification from smoking. Generally, as soon as you start to quit smoking, your body will slowly break down and excrete toxins. During the first 1-3 days of quitting, coughing and coughing up phlegm may be more severe, but persist for about 1 week and the cough will gradually reduce until it disappears. The coughing sputum may be mixed with black substances, which are harmful substances accumulated in the lungs and expelled from the body together with the sputum, which is also a manifestation of the body’s detoxification. It may take 1-2 years or more to completely detoxify your body from smoking, and the exact time varies from person to person. After quitting smoking, you should eat more fruits and vegetables, ensure nutritional intake, take vitamins to speed up the elimination of toxins, and strengthen physical exercise to keep your body healthy. In the process of quitting smoking, withdrawal symptoms may occur, such as weakness, difficulty sleeping and eating, chest tightness, shortness of breath, etc. It is important to persevere and not to give up halfway. If patients experience serious discomfort, they can go to the respiratory department of a regular hospital to seek help from a professional doctor to better survive the discomfort.