Withdrawal syndrome refers to the long-term use of a psychoactive substance, such as tobacco, alcohol, addictive drugs, etc. After addiction, due to the sudden reduction or cessation of use, a series of mental and neurological symptoms such as insomnia, irritability, etc., accompanied by nausea, vomiting, generalized pain, tremors and convulsions and other somatic reactions. It mainly includes smoking cessation syndrome, alcohol withdrawal syndrome and drug withdrawal syndrome, etc.: 1. Smoking cessation syndrome: long-term smokers who suddenly stop smoking will experience general weakness, irritability and other emotions, and even a series of addiction symptoms such as chest tightness, anxiety and dullness of sensation; 2. Alcohol withdrawal syndrome: long-term alcoholics who stop drinking alcohol will generally experience varying degrees of mental symptoms and physical symptoms. Mild withdrawal syndrome is characterized by weakness, sweating, hyperreflexia and symptoms of gastrointestinal dysfunction, such as nausea and vomiting; in severe cases, tremors and convulsions may occur, but generally not more than two episodes in a short period of time; 3, drug withdrawal syndrome: long-term use of addictive drugs, once weaned off the drug will appear withdrawal symptoms. The symptoms are anxiety, insomnia and anorexia, and delirium can occur in severe cases; autonomic hyperactivity is mainly manifested by sweating, sweat, goose bumps, runny nose, tears, dilated pupils, increased body temperature, accelerated pulse rate, increased blood pressure, accelerated breathing, diffuse pain in muscles, bones, joints and low back, and muscle tremors. As a result of not eating and drinking, combined with vomiting, sweating and diarrhea, there is significant weight loss, and in severe cases, even death by emaciation. People who have addiction to smoking, drinking or other psychoactive substances can gradually reduce the amount, or can be replaced by substitutes with weaker effects, such as e-cigarettes, drinks, etc., and later also gradually decreasing substitutes until discontinued, which can better achieve the purpose of preventing withdrawal syndrome.