Thyroid Testing and Diagnosis

Thyroid Blood Tests, Imaging Tests, Biopsies, and Other Tests

Technician holding blood sample
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Many people wonder how to diagnose a thyroid problem.  Medical assessment includes thyroid tests and other types of evaluation.

Diagnosing thyroid disease is a process that can incorporate numerous factors, including clinical evaluation, blood tests, imaging tests, biopsies, and other tests.


A critical part of detecting and diagnosing thyroid disease is the clinical evaluation conducted by a trained practitioner.

As part of a thorough clinical evaluation, your practitioner typically should do the following:

  • Feel (also known as “palpating”) your neck.
  • Listen to your thyroid using a stethoscope.
  • Test your reflexes.
  • Check your heart rate, rhythm and blood pressure.
  • Measure your weight.
  • Measure body temperature.
  • Examine your face.
  • Examine your eyes.
  • Observe the general quantity and quality of your hair.
  • Examine your skin.
  • Examine your nails and hands.
  • Review other clinical signs

Find out more about the specifics of the clinical evaluation for thyroid disease in this article.


The blood tests that may be done as part of a thyroid diagnosis include the following:

  • Thyroid Stimulating Hormone (TSH) Test
  • Total T4/ Total Thyroxine
  • Free T4 / Free Thyroxine
  • Total T3 / Total Triiodothyronine
  • Free T3 / Free Triiodothyronine
  • Thyroglobulin/Thyroid Binding Globulin/TBG
  • T3 Resin Uptake (T3RU)
  • Reverse T3
  • Thyroid Peroxidase Antibodies (TPOAb) / Antithyroid Peroxidase Antibodies
  • Antithyroid Microsomal Antibodies / Antimicrosomal Antibodies
  • Thyroglobulin Antibodies / Antithyroglobulin Antibodies
  • Thyroid Receptor Antibodies (TRAb)
  • Thyroid-Stimulating Immunoglobulins (TSI)

Find out more about these blood tests for thyroid disease in this article.


A number of imaging tests are performed for diagnosis of various thyroid conditions.

These tests include:

  • Nuclear Scan / Radioactive Iodine Uptake (RAI-U) – which can tell whether a person has Graves' disease, toxic multinodular goiter, or thyroiditis.
  • CT Scan – to help detect and diagnose a goiter, or larger thyroid nodules.
  • MRI / Magnetic Resonance Imaging – to evaluate the size and shape of the thyroid
  • Thyroid Ultrasound – to evaluate nodules, lumps and enlargement of your gland. Ultrasound can tell whether a nodule is a fluid-filled cyst, or a mass of solid tissue.

Find out more about these imaging tests for thyroid disease in this article.


A needle biopsy, also known as fine needle aspiration (FNA) is used to help evaluate lumps or cold nodules. In a needle biopsy, a thin needle is inserted directly into the lump, some cells are withdrawn and they are evaluated for cancer. (Some practitioners use ultrasound while conducting a biopsy in order to ensure that the needle goes into the right position.) Cancer can be definitively diagnosed about 75 percent of the time from FNA.

Evaluation of biopsy results can also show cells indicative of Hashimoto’s thyroiditis.

Find out more about fine needle aspiration (FNA) biopsy of the thyroid in this Q&A article.


Practitioners sometimes use other diagnostic tests and procedures to identify thyroid dysfunction. The use of these tests is considered controversial to mainstream practitioners, but many of these tests are well-accepted and in use among alternative, integrative and holistic physicians. These tests include:

  • Iodine Patch Tests
  • Saliva Testing
  • Urinary Testing
  • Basal Body Temperature Testing

Find out more about unconventional diagnostic tests in this article.


Some patients need to be highly involved in their thyroid diagnosis and care, which is where self-tests and the ability to order your own tests can be a critical tool for an empowered patient. Among the options for patients include:

  • The Thyroid Neck Check – A check you can perform yourself.
  • Blood Tests, including Anti-Thyroid Antibodies (Thyroglobulin Antibodies and Thyroid Peroxidase Antibodies), Free T4, Free T3, Reverse T3, and more
  • ZRT Laboratory’s Saliva and Bloodspot Testing, including TSH, Free T4, Free T3, and Thyroid Peroxidase (TPO) Antibody.
  • Diagnostechs Saliva Testing, including TSH, Free T4, Free T3, and antimicrosomal antibodies.

Find out more about self-tests, and how to order your own thyroid tests in this article.


Being informed and knowledgeable about thyroid disease signs, symptoms and risks can be an important part of getting properly diagnosed.

Interactive thyroid quizzes are important tools to help you identify risks and symptoms in particular areas.

Other tools that can be helpful in preparing for a visit with your physician, or during the actual examination, are checklists of risks and symptoms.


Diagnosis of various thyroid disease and conditions involves clinical examination, blood tests, and in some cases, imaging tests and/or biopsy. There are different tests and procedures used to diagnose the following thyroid problems:

  • Hypothyroidism
  • Hashimoto’s Disease
  • Hyperthyroidism
  • Graves’ Disease
  • Goiter
  • Nodules
  • Thyroid Cancer

Find out about specific diagnostic tests and steps in this article.


Braverman, MD, Lewis E., and Robert D. Utiger, MD. Werner and Ingbar's The Thyroid: A Fundamental and Clinical Text. 9th ed., Philadelphia: Lippincott Williams & Wilkins (LWW), 2005.

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