Hypothyroid 101

Hypothyroid 101 provides an overview of what the thyroid does, the main thyroid hormones, the main causes of hypothyroidism, how hypothyroidism is diagnosed, as well as options for having thyroid blood tests done.

The Thyroid Gland

hypothyroid - the thyroidThe thyroid is butterfly-shaped gland situated in the middle of the lower front part of the neck. While it isn’t very big, it plays a very important role in the regulation of metabolism which is the process by which the food we eat is converted to energy.

When the thyroid doesn’t function properly, it affects metabolism. In the case that the thyroid is underactive (hypothyroid) this results in a slowing of everything from heart rate, our ability to generate heat to stay warm, for muscles to do work, and for us to think properly and process information.

The Two Main Thyroid Hormones – T4 and T3

The thyroid produces two main hormones, T4 (thyroxine) and T3 (triiodothyronine). When it’s working properly, 93% of the thyroid hormone produced by the body each day is T4, and only 7% is T3 [1]. The thyroid manufactures ~85mcg of T4 and 6.5mcg of T3 per day [1], which is a T4 to T3 ratio of 13:1.  

T4 is the inactive form of thyroid hormone and has four molecules of iodide bound to it. When it becomes activated, it loses one of the iodides and becomes T3, which is the active form.

In its free, unbound form, thyroxine is known as free T4 (abbreviated fT4) and in its free, unbound form triiodothyronine is known as free T3 (abbreviated fT3). 

The production of T4 and T3 in the thyroid is regulated by the pituitary gland, but the signal for the pituitary gland to tell the thyroid gland to make thyroid hormones comes from the hypothalamus region of the brain.  The hypothalamus releases a hormone called TRH (Thyrotropin-Releasing Factor) that acts on the pituitary gland, causing it to release a hormone called TSH (Thyroid Stimulating Hormone). It is TSH released from the pituitary gland that acts on the thyroid gland, causing it to release thyroxine.


hypothyroid - the Hypothalamus Pituitary Thyroid Axis
from [2] The Merck Manual of Medical Information (1997)

Hypothyroid – how it is diagnosed

In Canada and many places in the US, the standard screening test for abnormal thyroid function, including hypothyroid, is a blood test measuring thyroid stimulating hormone (TSH), which is a pituitary hormone. 

If TSH results falls within normal range, no testing of thyroid hormones occurs. The thyroid response to TSH is presumed to be normal. 

Central Hypothyroidism occurs when there is a problem with either the hypothalamus or the pituitary gland.

On lab tests, a low TSH and low free T4 indicates central hypothyroidism and this is often treated by prescribing medication, including T3 containing medications. 

Primary hypothyroidism is where there is no abnormality in the hypothalamus or the pituitary gland. It is diagnosed when there is high TSH, and normal or low free T4.

Hypothyroid – main causes 

In the developed world, the most common form of primary hypothyroid in is Hashimoto’s disease. In developing countries, it is mostly caused from a lack of iodine in the diet. Other causes of hypothyroid includes the trauma from surgery to remove a benign or cancerous tumour, or the result of radioactive iodine treatment for overactive thyroid.

Hashimoto’s disease is the most common cause of hypothyroid in the West. It is an autoimmune disorder where the body’s immune system, specifically the lymphocytes attack the thyroid. In response to this attack,  the thyroid produces antibodies, specifically thyroperoxidase antibodies (TPO-ab) and thyroglobulin antibodies (TG-ab) [3]. A diagnosis of Hashimoto’s is made based on both the presence of symptoms of hypothyroidism, as well as the presence of TPO-ab or TG-ab.

One of the main challenges with getting diagnosed as hypothyroid is that many of the early symptoms of hypothyroidism are non-specific  — meaning they can have several different causes.

In a post-pandemic world of telephone doctor appointments, such vague symptoms may seem too inconsequential to bring up.

Below is a downloadable checklist that can help you have a conversation with your doctor.

Symptoms such as body aches, joint pain, fatigue, feel chilled, weight gain, frequently being constipation, having dry skin don’t seem ‘serious’ enough to make an appointment with one’s doctor and could be due to a number of different causes from  not eating well, to having a virus, and are very often discounted as being due to “age”. Even forgetfulness and depression which are known symptoms in more advanced hypothyroidism are often attributed to aging. 

Hypothyroid – getting evaluated and diagnosed 

As outlined in an earlier article, in British Columbia unless a person is of advanced age, has a family history or personal medical history of thyroid disease or another autoimmune disorder, takes medications such as lithium or amiodarone, or is from a developing country with iodine deficiency, they do not even qualify for TSH testing unless they display the specific symptoms listed in Table 1, below [4].

hypothyroid signs and symptoms
Table 1: Signs and Symptoms of Hypothyroidism (from [4])

One drawback to the above approved checklist is that it does not include some of the well-documented symptoms of hypothyroidism, such as non-pitting edema of the lower legs and ankles, a puffy swollen face, an enlarged tongue (with or without scalloped edges), loss of the outer third of eyebrows, or having pale or bluish lips.

Even if one has a blood test for TSH, if it comes back at the high end of the normal range, no further testing is done [4]. 

hypothyroid diagnosis decision tree (in British Columbia)

Without a person having known risk factors, or having symptoms that appear in the official  list in the Guidelines and Protocols [4] (Table 1, above), diagnostic tests may not be requisitioned unless or until a person becomes sicker and the reason for this is explained below, in the section about ordering lab tests.

To help people have an informed discussion with their doctor, below is a 2-page downloadable, fillable checklist that contains a list of common hypothyroid symptoms, along with a simple explanation of what that symptom is. For example, in this checklist “periorbital edema” is explained as ‘swelling under eyes.’

Please note that this checklist list is not exhaustive and is NOT intended to be used for self-diagnosis purposes. It is only provided so that people who think they may have symptoms of hypothyroidism can consult with their doctor, and discuss the matter with them. Remember, only a medical doctor can diagnose and treat. 

Signs and Symptoms of Hypothyroidism – 2-page downloadable and fillable checklist


Thyroid Panel Lab Tests –  3 options to diagnose hypothyroid

[updated: November 3, 2022]

In Canada, there is no such thing as a standard “thyroid panel,” although naturopaths offer thyroid assessment panels on a client-pay basis. Medical doctors can order thyroid function tests based on the guidelines of their specific province, and naturopaths can order different thyroid assessment panels, depending on the province they are located in.

1. Medical Doctor (MD)

Thyroid function blood tests can be ordered by medical doctors (MDs) including family practice physicians, general practitioners (GPs), and specialists such as Endocrinologists and the cost of testing will be covered by the provincial health plan if it meets their guidelines. 

In most provinces in Canada, a requisition needs to be written by a licensed medical doctor for the cost of the test to be covered by the provincial health plan. In New Brunswick and Nova Scotia Health authorities and lab regulators have placed restrictions on how lab tests can be ordered, and patents are charged fees to order them privately.

In Ontario, Saskatchewan and British Columbia, the following guidelines apply;

Furthermore, in British Columbia, physician-ordered lab tests must be requisitioned in accordance with the Laboratory Services Act to be covered by MSP (Medical Service Plan). Doctors are in a very challenging position in BC as MSP can seek recovery for lab-test cost from a doctor if they feel that the test(s) ordered were not clinical  justified. 

Most physician-initiated lab test investigation for hypothyroid begins with a TSH test. One reason for this is to rule out Central Hypothyroidism which is where there is a problem with either the hypothalamus, or the pituitary gland. As explained above, a low TSH will likely result in a free T4 test being requisitioned. If free T4 is also low, then T3 medication or some other type of medication might be prescribed, or the person referred to an endocrinologist.

If the TSH test comes back high (above the upper limit of normal) this will likely result in a free T4 test being requisitioned. Depending on whether the free T4 is normal or low, and how far above the upper limit the TSH is, the doctor may recommend one of a variety of treatment options, and/or refer their patient to an endocrinologist.
The provincial health plan in British Columbia (MSP) pays the laboratory that performs the analysis the following amount for thyroid function tests, and thyroid antibody tests:
      • TSH: $9.90
      • free T4: $12.12
      • free T3: $9.35
      • thyroperoxidase antibody (TPO-ab): $20.22 (payable only for possible autoimmune thyroid disease)
      • thyroglobin antibody (TG-ab): $27.90 (only performed as an adjunct to thyroglobulin measurement for the conditions such as thyroid tumors, cancer, etc.)
      • reverse T3: uninsured test 
from http://www.bccss.org/bcaplm-site/Documents/Programs/laboratory_services_schedule_of_fees.pdf
Where it becomes challenging is when TSH is in the high-normal range and/or the person has symptoms consistent with being hypothyroid but no symptoms listed on Table 1 of the Guidelines & Protocols for Thyroid Function Testing [4]. In BC, it used to be up to a physician’s discretion to requisition blood tests based on their best clinical judgement, but since the Laboratory Services Act (LSA) came into effect on October 1, 2015 [5], the Medical Service Plan (MSP) can seek recovery for lab-test cost from the doctor if they feel that the test(s) ordered were not clinical  justified. Needless to say, this puts doctors in a very challenging position.
As a clinician, when I provide one of my clients with a Lab Test Request Form to bring to their doctor, with their permission I will mark the clinical reason that I am requesting specific tests to rule out hypothyroid on the form, so that their doctor can consider whether they feel the test(s) are warranted.

2. Naturopathic doctor (ND)

[updated: November 3, 2022] 
In British Columbia, Ontario and Saskatchewan, thyroid assessment panels require a visit to a naturopath, and would take at least two sequential visits; one to get the lab test requisition to go to the lab, and the second to have the naturopath provide their interpretations of the results, and their recommendations. The costs of naturopath’s services are not covered by provincial health care, so clients need to pay out of pocket.  Fees for naturopathic visits and blood test vary between provinces and within the same province between practitioners.
In Ontario, fees for visits to a naturopath are regulated by the College of Naturopaths of Ontario and are set per block of time . Typically the cost of first visit, second visit and subsequent visits vary, with the first visit of 75 minutes costing ~$200, and the second visit of 45 minutes) costing ~$115. 
In the first visit the naturopath would ask questions as part of their assessment and complete and sign a Naturopathic Requisition Form which enables their client to go to the lab and have the tests done. The client pays the naturopath for the visit as well as the cost of the lab tests. In Ontario, the College of Naturopaths of Ontario allows naturopaths to add a markup to goods and services they offer, such as supplements, and blood test panels. With respect to blood tests, the naturopath pays a special negotiated lab fee for the thyroid panel to the lab, then bills their clients, often with a mark-up.   In the second visit, the naturopath will interpret the results.
In BC, fees are set by the BC Naturopathic Association Fee Guidelines. Naturopaths are also able to add a mark-up to the cost of supplements and blood tests. From experience, some naturopaths in BC keep their mark-up for lab tests minimal (e.g. $7 per test).  
The Enhanced Thyroid Assessment available in Ontario has the following 6 tests ;
    • TSH
    • Free Thyroxine (FT4)
    • Free Triiodothyronine (FT3)
    • Reverse T3
    • Thyroperoxidase Antibody (TPO-ab)
    • Anti-Thyroglobulin (TG-ab)
Prices for thyroid panels charged to naturopaths are available online for Ontario (see above) but in BC the prices aren’t marked.
Compared to the (MSP) government pricing, the above tests (minus the Reverse T3 which isn’t paid for by MSP) costs $80, so presumably naturopaths are charged prices similar to what MSP pays and then can add a mark-up to them. From the client’s perspective, they need to pay for the two naturopath visits, as well as the cost of the lab tests. 
    • TSH: $9.90
    • free T4: $12.12
    • free T3: $9.35
    • thyroperoxidase antibody (TPO-ab): $20.22 (payable only for possible autoimmune thyroid disease)
    • thyroglobin antibody (TG-ab): $27.90 (only performed as an adjunct to thyroglobulin measurement for the conditions such as thyroid tumors, cancer, etc.)
Total: $79.49
In British Columbia, naturopaths can only order the Basic Thyroid Assessment which includes the following 4 tests;
    • TSH
    • Free Thyroxine (FT4)
    • Free Triiodothyronine (FT3)
    • Thyroperoxidase Antibody (TPO-ab)

Reverse T3 and Anti-Thyroglobulin (TG-ab) are not available.

3. Patient-Pay 

If a doctor does not want to take the risk of requisitioning specific lab tests that the provincial plan may seek to recover costs from them, there is the option of the doctor writing on the requisition that specific test(s) to rule out hypothyroid will be “patient-pay” and the individual can pay for that specific lab test themselves. 
It should be made clear that a person does need a requisition from a doctor that indicates “patient pay” for the specific test(s) and cannot go to the lab directly and request the test themselves.
***It should also be noted that the cost of thyroid lab tests paid for by the individual are NOT the same as the cost paid for by MSP, and naturopaths, but are significantly higher. 
Last week, as a private individual with a physician lab requisition, I was charged 3 times the MSP cost for a free T3 test. As I found out at that lab visit, there is no patient-pay price list available at the lab, online, or by writing the lab office. The staff at the lab will disclose the cost of the test once the person is at the lab with the requisition, but this first requires the individual making an appointment, and going there at their appointment time.  
A fellow clinician told me several days later that there is a patient-pay price list available to Physicians, Registered Dietitians, Nurse-Practitioners, and other healthcare professionals, and I now have a copy of this list. It is titled the British Columbia Private Price List for Commonly Ordered Lab Tests, and is dated April 2021. It is labelled as “a confidential document,” and it is indicated at the top that clinicians are not to disclose their prices publicly, however we are able to share that information in conversations with our patients / clients. 
While I am unable to disclose the patient-pay lab test prices publicly (such as in this article), I am able to share the patient-pay prices of lab tests with any of my clients who are considering asking their doctor to requisition patient-pay test(s).  

Final Thoughts

Determining whether the symptoms one has may be related to their thyroid, and going about getting tested can be challenging. It is my hope that by providing the information in this article, you can have an informed discussion with your doctor.

If you would like more information about how I can support you in your goal of improved health, please send me a note through the Contact Me form above.

To your good health!



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  1. Jonklaas J, Bianco AC, Bauer AJ, et al, Guidelines for the treatment of hypothyroidism: prepared by the American thyroid association task force on thyroid hormone replacement. thyroid. 2014 Dec 1;24(12):1670-751.
  2. Berkow, R., Beers, M. H., & Fletcher, A. J. (1997). The Merck Manual of Medical Information. Whitehouse Station, N.J.: Merck Research Laboratories.
  3. Puszkarz, Irena, Guty, Edyta, Stefaniak, Iwona, & Bonarek, Aleksandra. (2018). Role of food and nutrition in pathogenesis and prevention of Hashimoto’s thyroiditis. https://doi.org/10.5281/zenodo.1320419
  4. BC Guidelines & Protocols Advisory Committee, Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder, October 24, 2018
  5. Laboratory Services Act, Laboratory Service Regulation, October 1, 2015 (last amended September 20, 2020 by B.C. Reg. 263/2020)


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