Malignant thyroid nodules refer to thyroid nodules that are malignant in nature, mostly referring to thyroid cancer, and in rare cases, metastases or malignant lymphoma, etc. Thyroid cancer accounts for a relatively low percentage of malignant tumors in the whole body, about 1%. It mostly originates from follicular epithelial cells and is mainly classified into: papillary carcinoma, follicular carcinoma, undifferentiated carcinoma, medullary carcinoma, etc. Papillary carcinoma: the most common type of thyroid tumor, mostly found in young and middle-aged women, with good differentiation, slow growth, low malignancy and very good effect of early surgery. Follicular carcinoma: Commonly found in middle-aged women, it is a moderate malignant condition with a prognosis inferior to papillary carcinoma. 3.Undifferentiated carcinoma: highly malignant, mostly seen in the elderly, often accompanied by metastasis, with very low five-year survival rate. 4.Medullary carcinoma: less common, moderately malignant, can occur nearby and distant metastasis. The performance of different types of tumors is not exactly the same, however, all of them will have the performance of local lumps, and some patients may have metastatic symptoms, such as hoarseness, difficulty in swallowing, etc., which require timely examination to clarify the condition. All in all, regular medical checkups must be conducted daily for early detection of lesions and early intervention.