There is no clear correlation between thyroid nodules and hypothyroidism. For thyroid nodules combined with hypothyroidism, hypothyroidism needs to be corrected. Most hypothyroidism is caused by destruction of thyroid follicular cells and insufficient thyroid secretion, and hypothyroidism needs to be treated with oral replacement therapy with levothyroxine sodium tablets. As for the causes, most of them are related to the combination of Hashimoto’s thyroiditis or thyroid atrophy, and hypothyroidism is relatively easy to correct. If the ultrasound classification of thyroid nodules is above category 4 or 4, thyroid cancer cannot be completely ruled out and at least a fine needle aspiration is needed to further clarify the diagnosis. If a thyroid nodule combined with hypothyroidism requires surgery, lifelong hypothyroidism may occur after surgery, requiring long-term replacement therapy with levothyroxine sodium tablets.