6 Thyroid Lab Tests Every Patient Should Insist On (and What They Mean)

So, you just got back your “thyroid labs” and all they say is: TSH and Total T4. Your doctor might have even told you that “you do not have a thyroid problem” even though you are ticking every symptom of hypothyroidism (I’ve posted the symptoms list here.)

If you are lucky, the doctor would have also tested you for Total T3. If you are really lucky, the doctor would have ordered the Free T4 and maybe Free T3.

Why is it important to know if you want to manage your thyroid health? Here are a few reasons.

Reason #1: The TSH Controversy

TSH alone is not enough to manage your thyroid condition. There is a big push in the thyroid advocacy world against the blindness of doctors of using TSH to treat thyroid patients.

There are a few reasons for that. Firstly, the range used by conventional doctors is 0.5 – 5.0 whereby functional and integrative practitioners would want to see a healthy person to have their TSH in the 1-2 range.

You see, I also had a perfect TSH of 1.6 to 1.8 even when my body was completely shutting down. This is due to reason #2, see below.

Reason #2: T3 Hormone is King.

T3, also known as triiodothyronine, is the hormone that our body cells have receptors for. This means that for you to have beautiful hair, healthy nails, optimal gut health, a sharp mind and good mood, you need a sufficient amount of the T3 hormone, not T4.

Interestingly, the T3 hormone is produced from T4 by a metabolic conversion that happens in the gut and the liver. Can you see now how you could have a sufficient T4 hormone but if your T3 is low, you will still be feeling like a zombie?

Oh, and by the way, Synthroid is a synthetic version of T4 – this means that you still need to convert it to T3 to feel good.

Reason #3: Free and Not Total

Another problematic issue is that most doctors do not test for the “free” version of the T4 and T3 hormone. “Free” means unbound to a protein molecule and available for the body receptors to use so you can function properly.

Reason #4: The Overlooked Autoimmune Element

Remember that 90% of thyroid conditions in developed countries are due to an autoimmune condition, such as Hashimoto’s or Graves’. This means one thing: it’s our immune system primarily that is in trouble and starts launching an attack on the thyroid gland. If you have Hashimoto’s or Graves’, you do not have a thyroid disease but an autoimmune condition. This is really key to understand as your treatment plan will be vastly different.

How do you confirm having Hashimoto’s? By testing for the level of your TPO (thyroperoxidase) and TGB (thyroglobulin) antibodies.

Can you see now how useless and even dangerously misleading it is to have your TSH and Total T4 tested and nothing else?

But, there is more.

Reason #5: The T4 to T3 Conversion Issues

There is a list of vitamins and minerals that are key in converting T4 to T3. Vitamin and mineral deficiencies are very common in most people today. This is due to a combination of reasons – poor soil conditions of the food we grow, poor diet but also the highly compromised absorption ability of our gut.

When we experience poor digestive health even supplements can’t help as the gut lining is just not absorbing the goodness of the food we are eating.

Reason #6: Lab Ranges can be Tricky

Like mentioned above, a “normal” TSH range is accepted by the medical community to be from 0.5 to 5.0. If you think about it, it’s a pretty wide range with a multiplier of 10! To demonstrate an example: Amy might feel good when her TSH is at 0.8 while Marianne might need to be at 1.8 to feel like herself. If Amy’s TSH was 1.8 she would start feeling hypo and possibly put on weight, experience fatigue and foggy brain. If Marianne’s TSH was 0.8, she could start feeling hyper and experience heart palpitations, anxiety, problems feeling asleep, etc.

How a Good Diagnosis is Made

Can you see how tricky “normal ranges” can be? A good physician would therefore diagnose you based on three things:

1). Your family history (if your mom or grandma had thyroid issues, you might carry a genetic predisposition)

2). Your symptoms (which includes a physical examination of your thyroid), and

3). Complete thyroid labs.

You need to be your own advocate, don’t expect to have all the labs done right away.

Most doctors will not automatically test you for the below labs even though they are standard and insurance would pay for them (perhaps with the exception of the reverse T3).

Most doctors just order the TSH and Total T4 which I explained above, are useless. It is therefore paramount that you print out and take the checklist with you to the doctor’s office and insist on getting the full panel. Explain your symptoms and share with your doctor why TSH alone is not good enough. Back up your claim with a medical source and you can use Dr Izabella Wentz’s book to do so.

If the doctor refuses, move on and find a doctor who would. They do exist.

What to ask your doctor to test:

Complete Thyroid Panel: TSH, Free T4, Free T3, Reverse T3, TPO Antibodies, Anti-TGB Antibodies

Vitamins and minerals: These are key in converting T4 (inactive) hormone to T3 (active hormone): Ferritin, vitamin D and B12 at the very least.

Sugar levels: glucose (fasting blood sugar), HA1C and insulin.

Lipid Panel: Total cholesterol, LDL, HDL triglycerides.

If you want a printed copy of the above labs, grab a copy of the Thyroid Lab Checklist here.

Bring it to your doctor, it will feel empowering to be in the know. If your doctor dismisses you, find one that will do the complete tests.

Explanation of the thyroid markers

TSH – Thyroid Stimulating Hormone is released by the pituitary gland. This is the most commonly used (but not the most indicative) marker of thyroid health. TSH increases when T4 drops as the pituitary gland tries to “wake up” the thyroid by releasing more TSH to stimulate T4 production. In hypothyroid cases, TSH is typically high. This is a good starting point of a diagnosis but should not be used as the only marker. Typical lab range is 0.5-5.0 mU/L whereby functional practitioners like to use 1-2 mU/L range.

Free T4 (FT4) – Measures the amount of free thyroxine found in the blood. T4 is produced by the thyroid gland when it binds with iodine. It is largely an inactive hormone that gets converted to T3, which is the active hormone.

Free T3 (FT3) – Measures free triiodothyroxine (Free T3) and is the best marker for measuring the amount of an active hormone available for our body cells to utilize.

Reverse T3 – This marker is elevated if a person went through a major trauma, surgery or severe chronic stress. When the body is under stress, instead of converting T4 to T3 (the active form of thyroid hormone), the body conserves energy by making what is known as Reverse T3 (rT3), an inactive form of the T3 hormone. A high rT3 will block T3 from entering the cells making all symptoms of hypothyroidism even worse.

TPO Antibodies – Thyroid peroxidase antibodies are an excellent marker to indicate the inflammation level of the immune system. TPOs are elevated in 75% of Hashimoto’s patients. They are often not tested by doctors as there is no medication they can prescribe to lower the antibodies.

TGB Antibodies – Thyroglobulin antibodies are used for two reasons: to evaluate the effectiveness of treatment for thyroid cancer and to monitor for thyroid cancer recurrence. Secondly, they can show up high when a woman is taking birth control pills and/or has elevated estrogen levels.

As I’m writing this article, I think to myself “Wow, I wish this information was available back in 2008 when I was first diagnosed and felt so lost and helpless.” So here you have it, I hope you find this information helpful in getting on your healing journey!

Looking for more guidance on healing your thyroid condition? Consider our safe, guided, step-by-step protocol tailored to women with thyroid and autoimmune conditions. It’s called Thyroid Detox, and you can try it here. 


As of November 13, 2018, you can now order your own labs, no more begging or convincing your doctor.  To learn more about this resource go here.

You can also learn more about beneficial supplements to balance your hormones with our FREE Supplement Guide.