The thyroid gland is the largest endocrine gland in the body and is located under the thyroid cartilage immediately in front of the third and fourth cartilage rings of the trachea, consisting of both lobes and the isthmus. Behind the thyroid gland are four parathyroid glands and the recurrent laryngeal nerve. The main function of the thyroid gland is to synthesize thyroid hormones and regulate the body’s metabolism. Disease classification: 1. simple goiter; 2. hyperthyroidism (complication of hyperthyroidism); 3. hypothyroidism; 4. thyroid nodules, thyroid adenoma; 5. acute suppurative thyroiditis; 6. subacute thyroiditis; 7. chronic lymphocytic thyroiditis. Thyroid tumors can be divided into benign tumors and malignant tumors. Clinically, thyroid tumors are often manifested as thyroid nodules only, so thyroid tumors and thyroid nodules are often confused with each other. In fact, nodules are only a morphological description. They include tumors, cysts, masses of normal tissue, and thyroid lumps caused by other diseases. Thyroid tumors are common, and the most common type of thyroid tumor is benign thyroid tumor. Thyroid cancer is uncommon, but there has been a yearly trend of increase in recent years. Surgery proves that 80% of single nodules are benign tumors and 20% are malignant. The incidence of tumor in single nodule is 15.6%-28.7%, while the incidence of cancer in multiple nodules is generally less than 10%. This means that a single nodule is several times more likely to be cancerous than a multiple nodule. In terms of gender, thyroid tumors are more common in females and their incidence rate is 4 times higher in females than in males, but in terms of the ratio of thyroid cancer to thyroid nodules, it is higher in males than in females. In each age group, the incidence rates of benign and malignant thyroid masses are similar, but the incidence rate of thyroid cancer is high in thyroid nodules in childhood, accounting for about 50%-71%. be particularly alert to the possibility of cancer.