The main difference between thyroid surgery and internal medicine is that there is a difference in the scope of treatment of the disease. The scope of treatment in internal medicine includes hypothyroidism, hyperthyroidism, and simple thyroiditis. Surgery, on the other hand, requires surgery for many diseases, especially for occupying lesions of the thyroid gland. These include thyroid adenomas or nodules, simple cysts, and, in the case of nodular goiter, a long history of secondary hyperthyroidism. Internal conditioning is also required prior to surgery, mainly to keep the basal metabolic rate within a controlled range, and surgery can be performed to avoid serious postoperative complications. As for malignant tumors occurring in the thyroid gland, early diagnosis should be promptly followed by radical resection, and simple Hashimoto’s disease, if symptoms of compression occur, also requires the option of further surgical treatment.