What your thyroid blood tests really mean

Understanding your thyroid test results

Your doctor may have told you that you have a problem with your thyroid and you’ve asked for the blood test results but now aren’t sure what to think. Or you suspect you have a thyroid issue and ordered tests privately, but apart from the given ranges, you are now lost at how to interpret! So let’s clarify a couple of things on the T4s T3s etc!

Prefer to watch the video? Click on the play button below!

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The most common is for your practitioner to order blood tests for TSH levels – Thyroid Stimulating Hormone. If this number is then out of whack, they may order follow up tests such as T4 and sometimes antibodies.

If you have ordered a thyroid panel privately, then you will have likely received TSH, T4 (free & total), T3 (free, total & re-uptake), and antibodies. A holistic practitioner is also more likely to order all of these.

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How your thyroid functions

When it comes to your thyroid functioning we have:

  • The hypothalamus that produces TRH – thyroid releasing hormone
  • The anterior pituitary gland that produces TSH – thryoid stimulating hormone. We also know this gland for the production of FSH & LH, which mature and release eggs.
  • The thyroid of course, which produces thyroid hormones T4 and a little bit of T3
  • The liver, which does most of the T4 to T3 converting. Also the gut does some of that work.

When it comes down to it, you will feel good when your T3 levels are adequate for your body. This is the thyroid hormone that your body can use.

Thyroid medication like Levothyroxine is the synthetic form of T4. This means it still needs to be converted to T3. If your liver or gut are however not working properly, you will still end up with low levels of T3.

If your body detects enough T3 and T4, the hypothalamus will reduce TRH and the anterior pituitary gland lowers TSH. The reverse is true as well, too little of the thyroid hormones and the glands are told to raise TRH & TSH to stimulate the thyroid.

I recommend watching the 2 minute video snippet below, unless you’ve already watched the entire video of course :).

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Testing your TSH

A lot of practitioner check thyroid function based on the level of TSH. However, as you can see, TSH doesn’t say anything about the thyroid, it says something about the anterior pituitary gland in the first place. A high TSH could be caused by several things in the chain being out of balance:

  • An imbalanced anterior pituitary gland. This is often a result of hormonal contraceptives use.
  • An imbalanced hypothalamus. Often due to stress.
  • A T4-T3 conversion problem. This can happen in cases of
    • Stress
    • Starvation/anorexia/insulin resistance
    • Steroids use
    • A taxed liver for example due to heavy metals
    • Poor gut health for example in cases of IBS, candida overgrowth, or frequent antibiotics use
    • Low progesterone which is often the case with women having issues trying to conceive anyway!
    • Low iodine as this is used by the thyroid to produce thyroid hormones
    • OR indeed lower thyroid function 🙂

How do you know what is going on?

TSH is still a good start to look at. However, you need to remember that a range is just a range and your optimal health may fall outside that range. Not only that, TSH ranges depend on race, sex, and age anyway! So there are ranges of ranges so to speak.

Sub-clinical hypothyroidism (under functioning thyroid that can’t be picked up yet in blood work) & auto immune thyroid disease is also often not picked up on until the thyroid is functioning really poorly. Ideally you are ahead of that!

There is also some discussion on what a good TSH level is anyway. Generally speaking, it is advised to have a TSH under 4.5. However, that disregards the fact that having a TSH under 0.5 will likely give hyperthyroid symptoms.

Also, newer research suggests there is a higher risk of miscarriages for women with a TSH level between 2.5 and 4.5. The reason for this was unclear as the T3/T4 hormones for these women were still fine. I suspect therefore that this has more to do with an imbalance anterior pituitary gland than the thyroid.

In any case, it is more important to include T3 & T4 ranges and put them next to your symptoms. If you feel well but your numbers are out of range, keep monitoring how you feel, but question if you need to start on medication!

If on the other hand you don’t feel well, and your thyroid hormones are in the lower range, consider that your thyroid may not be working optimally in your case.

Some people may feel better in the high range of TSH some in the lower.

Also, hyperthyroid symptoms are often not picked up on when TSH & T4 come out “normal”, when in fact T3 may be through the roof.

Many labs & practitioners use different ranges, but the ranges below are relatively common in North America & Europe.


North America


Europe / Australia / New Zealand



0,4 – 4,0 mU/l

Under 4.5 mU/l
0.5-2.5 mU/l

0,4 – 4,0 mU/l

Under 4.5 mU/l
0.5-2.5 mU/l


5.0 – 11.0 μg/dL

Upper 50th
(above 8)

64 – 154 nmol/l

Upper 50th
(above 109)

(free T4)

0.9 – 1.7 ng/dL

1.17-1.79 ng/dL

8 – 26 pmol/L

15-23 pmol/L


100 – 200 ng/dL

Upper 25th
(above 175)

1,2 – 3,4 nmol/l

Upper 25th
(above 2.85)

(free T3)

2.3 – 4.1 pg/mL

3.25-4.55 pg/mL

3 – 8 pmol/L

5-7 pmol/L


9.2-24.1 ng/dL

Bottom 50th
(under 16.65)

31.89-83.55 nmol/L

Bottom 50th
(under 57.73)

When looking at the T3 & T4 ranges, you can see these are pretty big as it is. This is also why many practitioners suggest a T4 in the upper upper 50th and a T3 in the upper 25th are ideal.

Testing reverse T3 (RT3)

RT3 (reverse T3) is converted by the body from T4. It is called an inactive form of T3. It is said that the body can’t use RT3. I think that’s debatable, I don’t think our bodies make any hormones for no reason at all, but that we just don’t know exactly what it’s function is yet.

RT3 tends to go up in times of stress of illness. Maybe that’s our clue, perhaps it is a survival kind of hormone or one that is needed in repair and inflammation processes?

Testing RT3 to check for stress levels or illness is a controversial topic. Many practitioners don’t find it useful while others ask for this test to spot if hypothyroid problems are related to (adrenal) stress. Something I do often talk about!

That doesn’t mean that I necessarily recommend the test to be done. If I suspect thyroid symptoms are a result of long term stress (either due to ongoing inflammation or emotional/mental stress) it is easy to tell from the case. A confirmation with elevated RT3 would then not chance my recommended lifestyle changes or treatment course.

However, if someone has had a panel done and their RT3 is well elevated, of course it does support my conclusions. If you want to test for adrenal stress or fatigue, a saliva test giving you a daily profile of your cortisol (long term stress) and DHEA would be the best option.

Thyroid antibodies

Thyroid antibodies we prefer to be close to zero. Some practitioners say that not everyone with antibodies will have problems with their thyroid, however I think it is only a matter of time. After all, if the thyroid is under attack, for one it says something about the immune system struggling and secondly how long can the tissue continue to function properly when it is constantly under attack?

In many cases earlier on TSH, T4 and T3 numbers will be normal while antibodies may already be raised. It isn’t usually until later stages then that thyroid hormone levels start to drop. So if thyroid issues are suspected and TSH is tested, I would always suggest T4 and antibodies as well.

In some cases the auto immune response leads to the destruction of thyroid cells (I know.. that sounds dramatic doesn’t it, it kind of is though). As a result the thyroid isn’t able to keep up with enough thyroid hormones – hypothyroidism. This is often diagnosed as Hashimoto’s.

In other cases, the auto immune response leads to the thyroid being overstimulated. The antibodies that are produced, have the same effect as the TSH that the anterior pituitary gland normally produces. As a result the thyroid produces too much of a good thing, making you hyperthyroid. This is usually diagnosed as Grave’s disease.


Thyroid peroxidase antibodies

Common in Hashimoto’s (leads to hypothyroidism).
Less common in Grave’s disease.


Tthyroglobulin antibodies

Common in Hashimoto’s (leads to hypothyroidism).
Less common in Grave’s disease.


Thyroid-stimulating immunoglobulin

Common in Grave’s disease (leads to hyperthyroidism)


TSH receptor binding antibody. Also known as TSH-binding inhibiting immunoglobulin or TBII

Common in Grave’s disease (leads to hyperthyroidism)

Most practitioners will tell you that antibodies can fluctuate over time but that they can never get better. I happily disagree with this as it completely is possible! With holistic treatment the auto immune reaction can be reduced, the body brought back into balance and the antibody drop follows. Two important factors are in these cases:

  • Detoxing metals, if appropriate

  • Addressing the inherited destructive and/or auto immune disease tendency. I only know of homeopathic treatment that is capable of this.

Do you have hypo- or hyperthyroid symptoms?

Whether you have lower range, higher range or out of range results, they don’t really matter as much (apart from the antibodies which may not give you symptoms at first) if you don’t lay them next to your symptoms. Your results need to be interpreted properly and matched with your symptoms.

Hypothyroid symptoms

Hyperthyroid symptoms

These can also occur when you have in fact adrenal fatigue. Read this article to learn how to discover the difference.

These can also come up if your thyroid medication is too high or when your under functioning thyroid is healing

Chart symptoms:

  • Temperatures in follicular phase. Under 97.2 °F / 36.2 °C is suspicious, under 97.0 / 36.1 is a problem!

  • Temperatures in luteal phase never hit 97.8 / 36.6

  • Heavy periods

Feeling cold easily
Slow heart beat
Weight gain
Puffy face / water retention

Forgetfulness & brain fog

Dry hair / skin / vagina
Brittle nails
Eyebrow hair loss

Pains, aches & stiffness – muscles, joints

Chart symptoms:

  • Temperatures in follicular phase.
    Over 98 °F / 36.6 °C.

  • Temperatures in luteal phase over 99 / 37.2

  • Irregular cycles / periods

Feeling hot easily &
Weight loss
Frequent bowel movements
Eyes bulging & tremors

Anxiety, nervousness & irritability

Hair loss
Soft nails

Muscle weakness

Because Hashimoto’s is an auto immune disease, apart from the hypothyroid symptoms, you can often see other immune issues such as food sensitivities and digestive problems.

Getting better

Even if you do have out of range blood results and are symptomatic, medication isn’t always needed or needed for ever (whit the exception of no longer having a thyroid of course!). Medication or not, it is important that you bring your body & back in balance and strengthen it’s own healing ability. Yes, that may mean removing certain things from your diet or adding in others, but that isn’t always the solution.

A thyroid issue comes up for a reason and looking for that reason is what is the most important to treat your thyroid. Recognizing a thyroid issues and inflammation on your chart before your blood panel is off, monitoring if your thyroid is healing, and detoxing heavy metals homeopathically, are all things you can learn on my program – The Fertility Reclaim!

You may also like the video below that covers 5 ways of starting to heal your thyroid.