A solitary thyroid nodule with a solid nodule, with or without envelope or calcification and abnormal blood flow, over 1 cm is an indication for surgery. If it is less than 1 cm, but the ultrasound shows an irregular nodule pattern with calcification or abnormal blood flow, it should also be treated surgically. If the nodule is a simple cyst, it can be relaxed to about 3 cm before surgery, because any larger will result in compression symptoms and may make future surgery difficult and increase the chance of injury. In addition, if the nodule is highly functional, surgery should be performed regardless of size. For multiple nodules, the indications for surgery can be relaxed. If there are no abnormal signs on ultrasound, the largest solid nodule can be larger than 1-2 cm, and it is best to operate early if there are symptoms of pressure, such as breath-holding or swallowing difficulties. If any of the nodes show calcification or abnormal blood flow, it is equivalent to a solitary nodule and should also be operated. For those who are on medication, if the nodules do not decrease in size but increase in size or change during treatment, the medication should be stopped and surgery should be performed. Patients with hyperthyroidism who develop nodules after medical treatment should also undergo surgery. Large nodular goiters or retrosternal goiters should be treated surgically.