Once a thyroid nodule is found, it is important to check the relevant thyroid function indicators, especially in the case of a high-functioning adenoma, also known as a toxic thyroid adenoma, which can secrete thyroid hormones on its own and cause hyperthyroidism. In short, thyroid nodules are one of the causes of hyperthyroidism. In the case of hyperthyroidism, it is a hypermetabolic syndrome in which the concentration of thyroid gland in the circulating blood is too high due to some stimulus other than the thyroid gland or an unexplained factor. This high concentration of thyroxine acts on all organs and tissues of the body, resulting in a series of clinical symptoms of hypermetabolism. Patients may often experience high fever, high heart rate, lethargy, fatigue, and irritability. Therefore, patients who have thyroid nodules and hyperthyroidism should be examined by ultrasonography for the combination of functional adenomas in the thyroid gland, as well as to take a review of the thyroid function for excessive thyroid function.