Issue # 91 April 15, 2013
Welcome to KnowYourThyroid.
I hope everyone is well.
Today, we will learn about thyroid testing. These are the follow-up tests that are performed to measure thyroid function after the initial blood tests show your thyroid hormone levels are too high or too low.
In today’s Check It Out I have a special offer for you if you would like to test your hormone levels on your own.
How is the diagnosis of thyroid disease made?
By Ruchi Mathur M.D.

Blood tests are often used to help determine thyroid function. Thyroid stimulating hormone (TSH) is often a screening tool and can be used along with serum T3 and T4 levels. If these hormones are abnormal, and further information regarding a possible cause is needed, antibody levels in the blood can be checked. Depending on the clinical situation, your doctor may look for specific antibodies such as:

  • Antithyroglobulin antibodies
  • Anti TPO antibodies
  • TSH receptor stimulating antibodies
  • If cancer is suspected, a thyroglobulin level may be ordered, and in rare circumstances, a calcitonin levels may be checked.


If there is concern about the structure of the gland, if size needs to be quantified or if there is a suspicion of cancer, imaging tests may be performed. Common modes of imaging include an ultrasound of the thyroid gland and radioiodine scanning and uptake. The ultrasound helps show size and consistency of the gland (for example, it is good at detecting cysts or calcifications within a gland), but it cannot always tell a benign gland from a cancerous gland. Ultrasounds may be done in a doctor’s office or in a hospital Radiology department.

Thyroid scans involve the use radioactively labeled form of iodine and are usually performed the Radiology department of a hospital or clinic. Since the thyroid is the only tissue in the human body that picks up iodine, the scan is very specific for finding thyroid tissue. If the thyroid is not picking up iodine normally, “spots” show up on the scan. A “cold” spot implies that the tissue is not picking up enough iodine compared to the rest of the gland. This may be seen in nonfunctioning nodules and may also be a sign of malignancy.

A “hot” spot implies that the tissues in that area is taking up more iodine than the surrounding tissue, and is overactive. This may be seen in a toxic nodule. Hot spots are rarely ever cancerous. In addition, there are comparison values to determine what normal thyroid uptake should be. A normal thyroid picks up 8%-35% of the administered dose of iodine within 24 hours. If values above or below this range is seen, it may point to underlying thyroid disease.


A biopsy provides a tissue sample for a pathologist to look at. This is usually the gold standard, especially when looking for diseases such as cancer. Thyroid biopsies are usually performed using a fine needle to aspirate cells from the gland. This is often referred to as fine needle aspirate or an FNA. FNAs can be done in a doctor’s office or in a clinic setting, and may involve an ultrasound machine to help guide the needle. Tissue samples can also be obtained during surgery. An FNA is a safe easily performed procedure, however, depending on the skill of the person performing the procedure, there is a chance that the aspiration may not yield enough tissue, or that the sampling is not of the right area.
For more information on Dr. Ruchi Mathur check out
Today’s  Check It Out is for those of you interested in testing your own hormone levels. I have a special for my readers to get $5 off a test kit. Just click the link below to get your discount.
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