In general, malignant thyroid nodules may be cancerous. Thyroid nodules are confined masses in the thyroid tissue following abnormal proliferation of thyroid cells. If a realistic nodule appears to be tissue hyperplasia within, has no endocrine function, has bleeding or cystic changes within the nodule, it may be thyroid cancer. Thyroid cancer is a malignant tumor originating from the follicular epithelial or parafollicular epithelial cells of the thyroid gland. It may be associated with a variety of factors, such as oncogenes, heredity, and ionizing radiation. Early stage patients of thyroid cancer usually do not have obvious symptoms, and as the tumor increases in size, it may show symptoms such as neck lump, neck pain, dyspnea, hoarseness, etc. when it presses the adjacent tissues. In addition, it is recommended that patients with malignant thyroid nodules should undergo regular checkups to observe their condition and receive treatment as early as possible if their condition deteriorates.