Thyroid Tests Your Doctor Never Told You About

We’ve written about thyroid testing in the past–it’s one of the most common concerns we hear from patients coming into the clinic.

If you take a peek at the symptoms of low thyroid, you can see why:

  • Exhaustion, weakness, and fatigue
  • Sensitivity to cold and reduced sweating
  • Shortness of breath when exercising
  • Slight to moderate weight gain
  • Problems with concentration or memory, slow thoughts or speech
  • Hair thinning and falling out
  • Crappy nails
  • Dry skin

Notice anything? Just about every women over 40 years of age who arrives in clinic has experienced one or more of these symptoms. And when they pay a visit to “Dr. Google” a thyroid problem is the first culprit on the list.

The Challenge of Thyroid Testing

Next step for most people is a trip to their MD, and a thyroid test. This is when things get complicated.

It’s not uncommon to get a blood test that comes back as “normal” (assuming you get one at all).

The problem is that you’re almost certainly only seeing part of the picture, and once you dig deeper, you realize that normal doesn’t necessarily mean optimal. Getting a true picture of thyroid function takes a closer look than you typically get from your MD.

There are several ways to test your thyroid function. We’ll take a look at them in more detail so you can understand why you might need more than just the first one.


TSH (thyroid stimulating hormone)

This is the test you’ll probably get from your MD–it’s the first stop on the thyroid testing road trip.

Confusingly, this isn’t a thyroid hormone at all, but a pituitary hormone. Its job is to stimulate the thyroid to make thyroid hormones when there isn’t enough in the blood.  So when TSH is high, that means the thyroid function is low and your body is sending signals to make more hormone.

There is, however, a whole lot of argument about what TSH numbers should be.

The TSH “normal range is 0.35-5.00, although in the past 10 was considered okay. Now, there are some endocrinologists who think even 3 is too high.

What do we think? When naturopathic doctors see this test come in anywhere over 2, we start to get interested and start digging deeper. Read on.

T4 (thyroxine)

This is a thyroid hormone, and it’s the main hormone produced by the thyroid. BUT…this form of the hormone isn’t actually active. It travels through the blood and goes to your cells where it needs to be absorbed and then converted to the active form of the hormone.

This conversion is dependant on minerals like zinc and selenium. In people who are deficient in these nutrients (not uncommon, particularly in those who have been taking synthetic thyroid drugs for years) this conversion doesn’t happen optimally.

That means you can get a “normal” T4 result, but things still can be out of whack. You may have lots of T4 around, but it’s not getting turned into actual active hormone.

T3 (triiodothyronine)

This is also a thyroid hormone, and it’s the active form. The thyroid makes this in much smaller amounts than T4. Most of your  T3 is made by converting it from T4 at the cellular level.

We use this result to tell us that the conversion process is working, and to get a sense of how much active hormone there is in your system

Reverse T3

In certain circumstances, instead of turning T4 into T3, the active form of the thyroid hormone, the cell it turns it into a reverseT3 instead. This can happen, for example, when you’ve got too much T4 around.

Reverse T3, as the name suggests, does the exact opposite of T3–it slows things down and CONSERVES energy. This conversion is NOT dependant on nutrients like the conversion to the active T3.

Again, this is a case where patients can “feel” hypothyroid even though regular blood tests would look normal.

Anti-TPO & Anti-TG (thyroid peroxidase antibody and thyroglobulin antibody)

These are not thyroid hormones but antibodies (immune molecules) that are attacking the thyroid. Anti-TPO is the most sensitive test for detecting autoimmune thyroid diseases such as Hashimoto thyroiditis or Graves disease and is usually the only one that need be done to screen for those conditions.

However, Anti-TG, or thyroglobulin antibody, will occasionally pick up autoimmunity when TPO is normal. When these antibodies are high this means the immune system is seeing the thyroid as an enemy, attacking it and causing it to under-function. Again, in this case you could get symptoms of low thyroid when a regular test would be normal.

The solution in this case is not to focus attention on the thyroid, but to help the immune system get back into balance so it stops putting undo stress on the thyroid.

The lesson here is that testing your thyroid function is a lot more involved than a quick TSH test. There are any number of reasons to get “normal” results, yet still have an underlying imbalance.

A good assessment of thyroid function means looking at lot more data, not just TSH. If you’re only getting TSH results, you’re not seeing the whole picture. Generally, we like to test TSH, T3, T4 and Anti TPO /Anti-TG, and reverse T3 when indicated.

Your little thyroid gland has its fingerprints all over your body–it can have far-reaching health effects. Helping it work optimally is something that can be done, but it’s a lot easier to do that with a complete picture of what’s going on.

For more information on thyroid testing, or to make an appointment, contact the clinic at 705-444-5331, or book online.


Don't miss another StoneTree article!

3 replies
  1. Tara Gignac
    Tara Gignac says:

    Hi Steven,
    The reflex test would be part of a physical exam that we would do here at the clinic.

    Thanks for the question,
    Dr. Tara

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *