The most intuitive indicator of thyroid disease is thyroid function measurement, which can determine whether the patient has normal thyroid function, hyperthyroidism, or hypothyroidism, and combined with the serum levels of thyroglobulin antibodies, peroxidase antibodies, or thyrotropin receptor antibodies, a very clear diagnosis of thyroid disease can be made. Ultrasound of the thyroid gland is only an auxiliary test. Ultrasound of the thyroid gland does not directly determine the functional status of the thyroid gland. In the case of hyperthyroidism, ultrasound of the thyroid gland indicates that the thyroid gland is rich in blood flow, further confirming the diagnosis of hyperthyroidism. Similarly, in hypothyroid patients, ultrasound of the thyroid gland indicates uneven echogenicity of the thyroid gland, which also confirms the diagnosis of Hashimoto’s thyroiditis and hypothyroidism from the side. Therefore, the diagnosis of thyroid disorders is based on thyroid function measurements, supplemented by thyroid ultrasound.