Hyperthyroidism Slideshow Pictures Take the Thyroid Disorder Quiz Thyroid Symptoms and Solutions Slideshow Pictures

Medical Author:

Stephanie L Lee, MD, PhD, FACE

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Thyroid Problems Diagnosis

The medical history and physical exam are important parts of the evaluation for thyroid problems. The health care practitioner will focus on eye, skin, cardiac (heart), and neurologic findings.

Blood tests

• Thyroid-stimulating hormone (TSH): In most cases, this is the single most useful lab test in diagnosing thyroid disease. When there is an excess of thyroid hormone in the blood, as in hyperthyroidism, the TSH is low. When there is too little thyroid hormone, as in hypothyroidism, the TSH is high.
  
  
• Free (T4): T4 is one of the thyroid hormones. High T4 may indicate hyperthyroidism. Low T4 may indicate hypothyroidism.
  
  
• Triiodothyronine (T3): T3 is another one of the thyroid hormones. High T3 may indicate hyperthyroidism. Low T3 may indicate hypothyroidism.
  
  
• TSH receptor antibody (TSI): This antibody is present in Grave's disease.
  
  
• Antithyroid antibody: This antibody is present in Hashimoto's and Grave's disease.

Nuclear thyroid scan: During this scan a small amount of radioactive iodine is swallowed or a similar material 99m-technetium, is injected into the blood, and then an imaging study of the thyroid is taken that reveals localization of the radioactivity. Increased uptake of the radioactive material in the thyroid gland indicates hyperthyroidism, while decreased uptake is present in hypothyroidism. This test should not be performed on women who are pregnant.

Thyroid ultrasound: Thyroid ultrasound helps to determine the size and number as well as the different types of nodules in the thyroid gland. This exam can also detect if there are enlarged parathyroid glands or lymph nodes near the thyroid gland.

Fine-needle aspiration: During this procedure, a small needle is inserted into the thyroid gland in order to get a sample of thyroid tissue, usually from a nodule. This test can be done in a health care practitioner's office without special preparations. The tissue is then observed under a microscope by a pathologist to look for any signs of cancer.

Computerized axial tomography (CT) scan: A CT scan is occasionally used to look for the extent of a large goiter into the upper chest or to look for narrowing or displacement of the trachea (breathing tube) from the goiter.