Color ultrasound is useful in diagnosing thyroiditis, but it needs to be combined with other tests such as laboratory tests, and it is recommended to diagnose under the guidance of a doctor. Thyroiditis includes Hashimoto’s thyroiditis, subacute thyroiditis, etc. Under the ultrasound examination of Hashimoto’s thyroiditis, diffuse changes of the thyroid gland can be observed; the ultrasound examination of subacute thyroiditis reveals that the volume of the thyroid gland increases, hyperechoic changes are observed, and there may be no obvious nodular echoes, and the border of the thyroid gland is blurred. The blood flow signal may be unchanged. Therefore, color ultrasound is useful in diagnosing thyroiditis. In addition, it is also necessary to combine with other tests for diagnosis; Hashimoto’s thyroiditis can have elevated thyroglobulin antibodies and thyroid peroxidase antibodies, and when accompanied by hypothyroidism, there can be an increase in thyroid stimulating hormone and a decrease in thyroxine and triiodothyronine. Subacute thyroiditis can be seen with increased blood sedimentation, elevated C-reactive protein, and elevated white blood cells. In thyrotoxicosis, there may be elevated serum T3 and T4 and low thyroid iodine uptake; in hypothyroidism, there may be decreased serum T3 and T4 and elevated TSH. Patients suspected of having thyroiditis are advised to go to the hospital and ask the doctor to make a comprehensive judgment by combining their own conditions and relevant examinations.