Does your doctor buy into this common myth about thyroid lab testing?

Don’t you wish there was just one test that could explain if you have something wrong with your thyroid?

I so wish there was. It sure would make my job easier!

And the truth is that many doctors act as if there is one magic test to check your thyroid health.

What is that one test that doctors put so much faith in?

It’s called Thyroid Stimulating Hormone, usually abbreviated as TSH and also known as thyrotropin.

The TSH level is important to know and absolutely should be measured.


When I see a new client who has signs and symptoms of a thyroid problem, you better believe I’m running more than a TSH level.


Because TSH is only ONE piece of the puzzle.

TSH is a hormone that is sent from the brain to the thyroid. And it is REALLY important to know what the brain is telling the thyroid to do.

But TSH doesn’t tell me how much hormone your thyroid gland is actually making.

It doesn’t tell me how much of the inactive thyroid hormone (T4) is getting converted to active hormone (T3).

It doesn’t tell me how well your cells are using active thyroid hormone.

It doesn’t tell me if there is an autoimmune process like Hashimoto’s or Grave’s disease attacking your thyroid gland.

It doesn’t tell me how well your brain is functioning. For example, what if you have ever suffered a concussion or other brain trauma? This can affect the ability of the brain to send the right amount of TSH to the thyroid.

So what are some of the key tests that should be run in the case of a suspected thyroid issue?

TSH:  To what extent is the brain signaling the thyroid to make thyroid hormone? A high TSH helps make the diagnosis of hypothyroidism and a low level helps make the diagnosis of hyperthyroidism. I carefully monitor TSH when my client is on thyroid medication.

Free T3 & T4:  Is there an insufficiency or imbalance in the amount of active (T3) and precursor (T4) thyroid hormone circulating in the bloodstream? Are you converting T4 to T3 properly? Also can help make the diagnosis of hypothyroidism and hyperthyroidism.

Reverse T3: Is there too much thyroid hormone being converted to inactive Reverse T3 instead of active T3 hormone? If Reverse T3 is high while you are on medication, your dose may be too high or you may need more T3 hormone relative to T4. Reverse T3 can be high in the case of chronic disease.

Antibodies to TPO & Thyroglobulin:  Are autoimmune processes in your body attacking the thyroid gland? In the case of suspected Grave’s disease, antibodies to TSI may be elevated.

Complete Blood Count (CBC) & Ferritin: Are you anemic or low in iron stores? Low iron is common in women with hypothyroidism.  Macrocytic anemia due to deficiencies in folate or vitamin B-12  is also common.

Vitamin D: There is an association between low vitamin D levels, hypothyroidism and Hashimoto's. 

Other labs to consider:  

  • Adrenal and sex hormones like cortisol, estrogen, testosterone, DHEA, progesterone

  • Nutrient testing like zinc and iodine

  • Food sensitivity testing

  • Labs to check for chronic infections and for other autoimmune processes in the body

  • Testing your body burden of heavy metals and non-metal toxins that can disrupt thyroid function.

I also typically run a Thyroid Ultrasound on patients with known or suspected thyroid issues. This tells me if there are changes to the thyroid tissue that suggest an autoimmune process and/or if there are any thyroid nodules that may need a further look.

The upshot? TSH is a very useful test but it it only one piece of the thyroid puzzle. If it is normal and you are having symptoms of thyroid disease, additional testing should be strongly considered.