A review of hypothyroidism usually involves laboratory tests such as thyroid function tests and, if needed, thyroid ultrasound. Laboratory tests for hypothyroidism mainly include thyroid function tests as well as other hormone tests. Thyroid function tests include thyroid stimulating hormone, free thyroxine, and free triiodothyronine, which can be used to understand the current thyroid function and adjust the dosage of levothyroxine tablets. The morphology of the thyroid gland can also be examined using color ultrasound to watch for changes in size. Patients with hypothyroidism should visit the hospital regularly for review and timely adjustment of the dosage.