Thyroid nodules are a common clinical condition with a prevalence of about 40-50%, i.e., 4 to 5 out of every 10 people have thyroid nodules, with women being the most common. Some studies have speculated that the cause is related to daily iodine intake (too much or too little), history of radiation exposure, environmental pollution, and other factors. Because of the sudden surge in incidence in the early 1990s during the high-tech development of computers, some experts have suggested that there is a relationship with radiation from computer equipment, the scientific nature of which remains to be studied. I. What are the ancillary tests for thyroid? The main clinical methods for diagnosing thyroid nodules include thyroid ultrasound, thyroid fine needle aspiration pathology, neck CT, MRI, and thyroid function tests, but CT and MRI are not as clinically valuable as ultrasound, and CT is only indicated for post-sternal goiter, which requires preoperative assessment of how deep the lower pole of the enlarged thyroid gland is from the upper sternal notch to determine whether the chest needs to be prepared for opening. With regard to fine needle aspiration pathology, many patients ask questions or even request this type of test preoperatively. Although fine needle aspiration is the only non-surgical way to identify benign and malignant thyroid nodules, it is always an invasive test and is highly dependent on the level of the operating physician, single or multiple nodules, and the size of the nodule. Statistically, the probability of undiagnosed and suspected malignant lesions with fine needle aspiration is about 9.5% and 6.8%. In contrast, the probability of postoperative paraffin pathology results matching with thyroid ultrasound results is 90% according to incomplete statistics, compared to our thyroid ultrasound (which has a new technology for elasticity scoring). Therefore, to sum up, patients with thyroid nodules can mainly improve the thyroid ultrasound (with new technology of elasticity scoring) and routine laboratory tests before surgery. Second, which thyroid nodules need surgery? Many patients have a misconception here that nodules on the thyroid gland need to be cut out immediately, and often even have the question “My nodules are so big, should I have surgery?” These questions are often asked. In fact, not all thyroid nodules need to be removed surgically. The main indications for surgery for thyroid nodules are: thyroid nodules affecting the appearance and quality of life; thyroid nodules combined with hyperthyroidism; thyroid nodules compressing the trachea, test tube and other symptoms such as poor breathing and obstructed swallowing; goiter behind the sternum; thyroid nodules considered malignant. Once the above indications for surgery appear, you need to be admitted to the hospital for surgical treatment. Except for the above thyroid nodules, the main treatment is internal medicine and observation. 3. What are the precautions after thyroid nodule removal surgery? Patients who undergo thyroid surgery in our department are hospitalized for about 4-5 days and can resume normal diet after surgery. Depending on the amount of thyroid gland removed, you can decide whether to take oral euthyroxine (levothyroxine tablets) or not. If thyroid hormone supplementation is needed, thyroid function is usually retested 2 weeks after surgery and the dose of eugenol is adjusted. Patients who have undergone unilateral subtotal thyroidectomy or thyroid adenoma removal generally do not need to take Eugenol, while patients who have undergone bilateral subtotal thyroidectomy need to take it for 3-6 months until the remaining thyroid tissue secretes enough thyroid hormone. The medication can be stopped only after that. Patients who have undergone “bilateral subtotal thyroidectomy, total bilateral thyroidectomy, or thyroid cancer resection” need to take Eugenol for life to supplement their thyroid hormones. ”Transient hypoparathyroidism” is common in patients after thyroid surgery. These patients are prone to hypocalcemia caused by a decrease in parathyroid hormone levels, resulting in increased excitability of the limbs and facial muscles, resulting in a feeling of paralysis in mild cases or muscle twitching in severe cases. Once the above symptoms appear, they are usually maintained for about 3-6 months. Therefore, preventive calcium supplementation is an indispensable process after thyroid surgery. Patients who have undergone “radical thyroid cancer” (90% papillary carcinoma) are special because, in addition to the above mentioned precautions, they are routinely treated with 131I. In fact, 90% of thyroid cancers are papillary cancers. Although the lymph nodes in the neck metastasize early, these cancers are different from malignant tumors in the gastrointestinal tract, and the incidence of distant metastasis is lower. Therefore, even if the postoperative pathological result is diagnosed as papillary thyroid cancer, the 5-year survival rate can be over 90% as long as the treatment course is completed. As long as the surgical treatment of thyroid gland is performed, it is recommended to do at least one thyroid ultrasound observation every year after surgery. For patients with thyroid nodules, we need to pay attention to whether there is recurrence and malignancy. For patients with papillary thyroid cancer, we need to pay attention to whether there are enlarged lymph nodes in the neck bilaterally.