In general, a single nodule that is solid, with or without encapsulation or calcification and abnormal blood flow, more than 1 cm is an indication for surgically operable nodules, and if it is less than 1 cm, but ultrasound shows irregular nodule morphology 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 also depends on whether there are symptoms of compression, such as breath-holding or difficulty swallowing. If any of the nodules has calcification or abnormal blood flow, it is equivalent to a solitary nodule and should also be operated. For patients on medication, surgery should be discontinued if the nodules increase in size or change during treatment. Patients with hyperthyroidism who develop nodules after medical treatment should also have surgery. Large nodular goiters or retrosternal goiters should be treated surgically. For those who have had previous thyroid surgery and now have a recurrence, the above indications can also be taken into account for reoperation. For patients who have had previous radiation therapy to the head and neck, have a family history of medullary thyroid cancer or multiple endocrine neoplasia type II, are <20 or >65 years old, are male, have nodules that grow rapidly or suddenly within a short period of time, have hard nodules with indistinct margins, have fixed nodules, have enlarged lymph nodes in the neck, and have symptoms such as hoarseness, cough, dysphagia, or dyspnea, surgery should be performed as soon as possible regardless of the size or number of nodules. The nodes should be treated as soon as possible, regardless of their size or number.