Diagnosis of Hyperthyroidism
by Editorial Staff and Contributors
Your doctor will ask about your symptoms, medical history, and family history. A physical exam will be done. Recommended tests may include:
These tests measure the blood levels of thyroid hormones. This can be done by checking levels of thyroid stimulating hormone (TSH), free T4, and at times, free T3. The levels of these hormones determine the activity of the thyroid gland. Your blood may also be examined for thyroid antibodies, especially if you are pregnant.
This test is used to help define the cause of hyperthyroidism. The thyroid gland uses iodine to make thyroid hormones. For this test, you will orally ingest radioactive iodine. Some of it is taken up by the thyroid gland. The amount of radioactivity is then measured by a radiation counter. In Graves disease, the amount is elevated. This test is not done on children or pregnant women.
Thyroid Scan TOP
This test may be done at the same time as the radioiodine uptake to evaluate one or more problematic nodules. If suspected on exam, a thyroid ultrasound may also be done. A thyroid nodule may or may not be functioning and is termed hot if it makes too much thyroid hormone, or cold if it does not make any.
Hyperthyroidism. Endocrine Society Hormone Health Network website. Available at:
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Accessed November 28, 2017.
Hyperthyroidism and thyrotoxicosis. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated July 27, 2017. Accessed November 28, 2017.
Vaidya B, Pearce SH. Diagnosis and management of thyrotoxicosis. Brit Med J. 2014;349:g5128.
Wu SY, Weiss RE. Radioiodine imaging in the primary care of thyroid disease. Postgrad Med. 2006;119(2):70-77.
Last reviewed November 2018 by EBSCO Medical Review Board James Cornell, MD
Last Updated: 12/20/2014
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