Feeling short of breath and tightness in the chest the day after quitting smoking is a normal condition. After quitting smoking, due to the suspension of nicotine intake, there will be some uncomfortable reactions, chest tightness and shortness of breath, drowsiness or difficult to sleep, coughing, hunger, constipation, anxiety, difficulty in concentrating, craving for cigarettes, irritability, impatience, and increase in institutional volume. Therefore, it is normal to experience chest tightness and shortness of breath when quitting smoking at an early stage. In the process of tobacco combustion, carbon monoxide will enter the bloodstream, combined with hemoglobin, and the combination is tight, resulting in a decrease in the ability to transport oxygen, thus feeling tightness in the chest and shortness of breath, in the long term after the cessation of smoking will gradually reduce the symptoms of discomfort in the smoking cessation treatment process if necessary, then the use of medication with the intervention therapy to improve the rate of success of smoking cessation. The use of specific drugs need to be under the guidance of a professional doctor, do not judge the use of drugs, in order to avoid danger.