Feverishness is commonly associated with hyperthyroidism, or the pediatric hot body type. Hyperthyroidism is an autoimmune disease and its clinical manifestations are not limited to the thyroid gland, but are a multisystem syndrome. The clinical manifestations with diagnostic significance are especially noted for fear of heat, excessive sweating, agitation, hyperactivity with wasting, tachycardia at rest, specific eye signs, and enlargement of the thyroid gland. According to the cause of hyperthyroidism, it can be divided into three categories: primary, secondary and high-functioning adenoma. 1. Primary hyperthyroidism is the most common and refers to the presence of hyperfunctional symptoms along with an enlarged thyroid gland. Patients are mostly between the ages of 20 and 40. The enlarged gland is diffuse and symmetrical on both sides, often accompanied by protruding eyes, so it is also called “protruding goiter”. Secondary hyperthyroidism is less common, such as hyperthyroidism secondary to nodular goiter; the patient first has nodular goiter for many years, and only later develops hyperfunctional symptoms. The age of onset is usually above 40 years. The gland is nodular and enlarged, with many asymmetries on both sides, without eye protrusion, and prone to myocardial damage. 3. High-functioning adenoma is rare. There is a single autonomous high-functioning nodule in the thyroid gland, and the thyroid tissue around the nodule shows atrophic changes. The patient has no ocular protrusion.