Cold nodules of the thyroid gland are those that show a low concentration or reduced uptake of nuclei in the lesion during a nuclear scan of the thyroid gland. It is mainly seen in malignant tumors of the thyroid gland, especially in solitary, isolated lesions, where thyroid cancer is more likely and should be surgically removed in a timely manner. However, there are some patients with simple thyroid adenomas or nodules, or nodular goiter, which are usually multiple lesions and may show cold nodular changes on nuclear scan. Hot nodules are mainly high-functioning adenomas, and the patient may also have significant symptoms of hypermetabolism, which may require further surgical treatment. The cold and hot nodules shown by nuclear scan alone have some variability and need to be further determined based on the specific condition, symptoms, signs and, if necessary, puncture biopsy.