Withdrawal reactions vary from person to person. Some quitters can smoothly pass the discomfort period, while most quitters may experience withdrawal reactions, which usually fade away in 1-3 months. The nervous system of the smoker’s brain is stimulated by nicotine for a long period of time, resulting in dependence and addiction. After quitting, the sudden lack of nicotine source in the body will lead to endocrine and circulatory system disorders, and some people will experience a series of uncomfortable symptoms, such as chest tightness, fatigue, and lack of concentration, which are all withdrawal reactions to quitting smoking. Usually these symptoms are most severe within 1 week after quitting and usually fade away in 1-3 months, but some people still sometimes have the urge to smoke 3-6 months after quitting. In the process of quitting smoking, quitters need to have the determination to keep going and not give up halfway. If you experience extreme discomfort, it is recommended that you go to the respiratory department or psychology department of a regular hospital in a timely manner to seek help from a professional doctor to get through the discomfort and achieve the goal of quitting smoking completely.