Smoking cessation syndrome is medically known as nicotine withdrawal syndrome, which mainly causes symptoms such as irritability, dizziness, headache, insomnia and worry, coughing and sweating, decreased heart rate, and appetite or weight gain. Nicotine Withdrawal Syndrome is a series of reactions that occur when a regular smoker suddenly quits smoking, mainly including gastrointestinal and neurological discomforts, such as irritability, dizziness, headache, insomnia and anxiety, coughing and sweating, decreased heart rate, dry mouth and thirst, and appetite or weight gain. It is normal to experience these symptoms within 1-3 months of quitting smoking, so there is no need to be alarmed, and it is important to persevere in overcoming the discomfort and to have the confidence to quit smoking. If the discomfort persists or worsens, it should not be taken lightly, and it is best to consult a doctor and quit smoking under his or her guidance.