Thyroid tests include blood tests for thyroid function, thyroid ultrasound and other related tests, which are done to find out whether the thyroid function is normal or not. Commonly used thyroid blood tests include three items, free thyroxine, free triiodothyronine, and thyrotropin. 1. Free Thyroxine, FT4, is the main hormone secreted by the thyroid gland and is mainly used in the diagnosis of hyperthyroidism and hypothyroidism as well as in late stage monitoring. 2. Free triiodothyronine, FT3, mainly reflects the normal or abnormal function of the thyroid gland. 3. Thyrotropin: It is the hormone secreted by the pituitary gland to promote the growth of the thyroid gland. When the thyrotropin is high and the thyroid gland secretes FT3 and FT4, it is hypothyroidism; when the thyrotropin is low and the thyroid gland over secretes FT3 and FT4, it is hyperthyroidism. 4. Thyroid ultrasound: Thyroid ultrasound can detect thyroid nodules and diffuse thyroid lesions. If abnormalities are found in the thyroid examination, it is recommended to go to the hospital in time to get a clear diagnosis and follow the doctor’s instructions for treatment, so as to avoid delaying the condition.