With the exception of rare undifferentiated carcinomas with little surgical efficacy (most of them have only tracheal resection to relieve airway obstruction, with a survival of 3 months to 6 months) and rare medullary carcinomas (for which elevated blood calcitonin is a specific diagnostic indicator) with total excision and lymph node dissection in at least the central region, there is a wide variation in the extent of surgery for differentiated thyroid carcinomas in general, and papillary carcinomas in particular, the most common type (follicular thyroid carcinoma, prone to hematogenous metastasis to (follicular thyroid cancer, which is prone to hematologic metastasis to the lung bone, is not prone to metastasis to the cervical lymph nodes and is usually treated with total excision plus postoperative iodine 131). The presence of a slender recurrent laryngeal nerve near the thyroid gland, which innervates the vocal cords bilaterally, causes hoarseness on one side, and bilateral damage may also lead to dyspnea. There are also rice or green bean-sized parathyroid glands near the upper and lower thyroid lobes bilaterally, which are responsible for calcium and phosphorus metabolism in the body. Damage to or removal of 1-2 parathyroid glands will not have consequences, but damage to all of them will result in numbness, cramps in the hands and feet, and even laryngospasm. This is the risk associated with bilateral total excision, +/- bilateral or unilateral central zone lymph node dissection, vocal cord paralysis or parietal gland damage; in addition, the dose of thyroxine requiring lifelong replacement after total excision has to be increased. However, surgery on only one side, although the risk of surgery is significantly reduced and the dose of postoperative medication is reduced, there is a risk that the surgery will not be complete and that postoperative radioactive iodine 131 therapy will not be completed (if normal thyroid tissue is present, iodine 131 enters preferentially and affects the effectiveness of iodine uptake therapy for metastases), nor does it facilitate the use of Tg to monitor for recurrence. So, is it better to cut one side or both sides of the thyroid gland for thyroid surgery? Sometimes it is difficult for the physician or the patient to decide. Generally speaking, if the tumor is less than 1.5 cm, especially less than 1 cm, without invasion of the thyroid peritoneum and without obvious lymph node metastasis, one side of the thyroid gland is sufficient to be removed. For tumors larger than 4 cm, or invading extraperitoneal structures, such as trachea, esophagus, nerves, blood vessels, extensive skin, or extensive cervical lymph node metastasis, or poor malignancy as shown by puncture cytology, BRAF+ by tumor gene test, or lung bone metastasis already exists, total excision must be done, and postoperative iodine 131 nail or focal clearance (which we consider as the absolute indication or rigid demand for iodine 131 therapy ) and a higher dose of oral thyroxine (the medical term for this is “suppressive therapy”). Generally speaking, thyroid cancer is not treated routinely with chemotherapy (e.g., 5-fluorouracil, cisplatin, etc.) or external radiotherapy. Radiotherapy or targeted drug therapy (but with limited efficacy, side effects and high price) are only considered if the cancer cannot be removed or cut cleanly. Therefore, early detection and early standardized surgery is still very important. Tumors between 1-4 cm can be considered on a case-by-case basis and can be excised completely or on one side, as is the case with the new international guidelines. The larger the diameter of the tumor, the more multifocal it is, the more lymph node metastases, the male, the presence of nodules on the opposite side, and the family history of thyroid cancer, the more favorable total resection is. Because the left and right lobes of the thyroid gland are connected by the isthmus gland without clear demarcation, they are prone to intraglandular metastasis, and there are also multiple microscopic thyroid lesions occurring at the same time, which are rich in lymphatic and hematologic metastasis, so sometimes it is reasonable to complete total excision even for “early” thyroid cancer. However, because most papillary carcinomas, especially micro papillary carcinomas, are of low malignancy, i.e. inert biologically, slow to develop, and not easily metastasized, they can be resected on one side plus lymph node dissection in the central region (according to the Chinese guidelines we prepared, postoperative suppressive therapy such as eugenol should be mild, e.g. TSH is around 1.0, and iodine 131 therapy is not necessary), and some people even propose observation. We limited the observation cases to less than 5 mm, no envelope invasion, no lymph node metastasis, elderly women, and regular follow-up monitoring. What kind of surgery, more accurate and reasonable, will also be debated, and finally may require individualized diagnosis and treatment of malignant behavior at the genetic level of molecular biology, i.e., individualized precision medicine, and the road of exploration will be long. For benign nodules, surgery is generally considered only if they are larger than 3-5 cm. A single nodule, suspected adenoma, or follicular tumor, or male, 2-2.5 cm, can be considered for surgery based on puncture or intraoperative freezing, or even postoperative pathology, to do partial, lobar, or even total excision. Multiple nodes advocate total excision, complete, once and for all, but must prevent complications of paraglandular or nerve injury, we have had cases where surgery was performed every 5-10 years, to us it was 5 surgeries. As for the scope of lymph node dissection, the general emphasis is on routine ipsilateral central zone dissection (i.e., pre-tracheal, paratracheal, and anterior laryngeal, which is equivalent to the “inner ring”, and some experts believe that the central zone lymph nodes are the primary lesion). The lateral cervical area (along the carotid vein sheath, IIa, III, IV, equivalent to the “middle ring”) should be cleaned up only when it is obvious by hand, or when it is suggested by ultrasound or enhanced CT diagnosis. If lymph node metastasis is severe, lymph nodes in areas IIb and V (lateral and posterior neck, equivalent to the “outer ring”) should also be cleared. Sometimes the paratracheal lymph nodes behind the sternum, i.e., the lymph nodes in area VII, also need to be cleared. Special attention is paid to the complete clearance of the lymph nodes, including the surrounding fat and nodal tissue, rather than “strawberry picking” excision, as tiny metastatic lymph nodes may be left behind. Lymph node metastasis is not effective for iodine 131 treatment, so do not miss the surgical excision. Also, attention should be paid to prevent damage to the sublingual nerve, celiac lymphatics, blood vessels and other important structures in the neck. Some experts also believe that lymph node metastasis does not affect the patient’s prognosis and survival rate, do not excessively clear the lymph nodes, which may lead to paracrine gland damage, and do not clear the lymph nodes if the central area is not obvious, and do not perform additional surgical clearance if the recurrent lymph nodes are not larger than 10 mm to protect the patient’s quality of life, which is worthy of reference. As for the use of thoracic-mammary pathway lumpectomy or small incision in the neck with the aid of oral cavity mirror, or even transoral surgery, as long as the doctor is experienced, the tumor is not too late, and the patient is strongly willing to have no or small scars in the neck, all can be considered, and the principles and scope of surgery, and conventional open surgery are consistent.