The causes of thyroid cancer are similar to those of most other malignancies. The etiology of thyroid cancer is not yet clear, but some factors are found to be associated with its occurrence: The first is neck radiation. The thyroid is an endocrine organ, sensitive to radiation. Radiation exposure can potentially cause thyroid cells to become cancerous, especially in those who received high doses of neck radiation in childhood and are more susceptible to thyroid cancer. The second factor is genetics; some thyroid cancers have a clear genetic predisposition, the most typical being medullary thyroid cancer. The third point is that the rapid increase in the incidence rate of thyroid cancer is partly due to the advancement in early diagnostic techniques, allowing for the detection of many early-stage lesions. Of course, iodine intake has already been shown to be related to some benign thyroid conditions. However, its relationship with thyroid cancer requires further study.