Physiological reactions to smoking cessation may include thirst, drowsiness, coughing, lack of concentration, etc. Patients may experience a variety of physiological reactions, collectively referred to as withdrawal reactions, in the days or even weeks after they begin to quit smoking. 1. Thirst: The process of quitting smoking is often accompanied by thirst, and at this time it is necessary to increase the amount of water to help remove toxins from the body. 2. Drowsiness: nicotine in cigarettes has a refreshing effect, and when nicotine intake is interrupted during the process of quitting smoking, patients will experience drowsiness, which can often be overcome by prolonging nighttime sleep or increasing the number of lunch breaks. 3. Coughing: In the process of prolonged smoking, the lungs secrete mucus for self-protection. After quitting smoking, the mucus is loosened and discharged from the body, and the cilia move again, which usually leads to coughing. 4. Lack of concentration: The patient’s sense of space and distance will be deviated, the body will appear to float, and concentration can not be focused on the situation. It is recommended that patients should consult a doctor in time if they have any discomfort, and should not be negligent so as not to delay their condition.