Smoking is generally not recommended after iodine 131 for hyperthyroidism. Iodine 131 is a common treatment for hyperthyroidism, and there are a variety of precautions to be taken after treatment; patients are not allowed to smoke after this treatment. It is uncertain whether smoking affects the effect of iodine 131 treatment, but smoking itself can cause chronic bronchitis, lung cancer and other diseases, which is very harmful to health. Therefore, smoking is not recommended, and those who already smoke are advised to quit as soon as possible. After iodine 131 treatment for hyperthyroidism, you need to follow the doctor’s instructions for regular review, pay attention to a low iodine diet, moderate activity, avoid staying up all night, tiredness, emotional excitement, avoid smoking and alcohol, and if you have fatigue, edema and other discomforts, you should consult a doctor in a timely manner.