What should you ask your doctor about : Thyroid testing
Updated: Nov 9, 2018
We have all heard of the thyroid. But do you really know what it is? The official medical definition is:
“The thyroid (Latin: glandula thyreoidea) is a vitally important hormonal gland that plays a major role in the metabolism, growth and maturation of the human body. It helps to regulate many body functions by constantly releasing a steady amount of hormones into the bloodstream. More hormones are produced when the body needs more energy, like when it is growing or cold, or during pregnancy.
The organ is located in the front part of the neck below the voice box and has the shape of a butterfly: The two side lobes on the right and on the left are connected at the front by a narrow strip of tissue. The side lobes enclose the windpipe and end at the sides and behind the windpipe.” (1)
Hypothyroid, meaning the thyroid is not functioning at its optimal level, is an under diagnosed condition. Only about half of patients with this condition even know that they have it! It can be sluggish for many reasons including, but not limited to, autoimmune disorders, stress, and leaky gut syndrome. This typically affects more women than men, but men can be diagnosed with hypothyroidism as well.
It truly is amazing how this tiny butterfly gland can have control over every single system in our body!! Signs and symptoms of hypothyroidism include, but are not limited to:
Weight gainFatigue“Brain Fog”Hair lossConstipationSwelling in extremities (hands, ankles, feet etc)Unexplained depressionInsomniaMuscle and joint achesDry, flaky skinIrregular menstrual cycles
As I said above: the signs and symptoms of hypothyroidism are not limited to the ones listed.
With hypothyroidism, specifically Hashimoto’s disease (the autoimmune version of hypothyroidism and one of the most common thyroid problems), it is even more important now than ever to be aware of what lab tests should be ordered if you begin experiencing any of the tell-tale signs or symptoms.
In this blog post, we want to share what labs we tend to order when performing a “hypothyroid workup.” As a general rule, we proceed with these tests if a patient comes into our office and is experiencing at least 3 symptoms that could be linked to hypothyroidism. Now this does not mean we want you going into your doctor’s office demanding these to be performed. We want you to be able to educate yourself and have a dialogue with your primary care practitioner about the symptoms you have been experiencing and collaborate with them to come up with a proper workup panel.
Thyroid stimulating hormone (or TSH) is the first, most common thyroid lab performed by general practitioners. TSH comes from the pituitary gland and tells the thyroid to produce enough hormone (free T4 and free T3) to keep your body’s systems happy and healthy.
The range for TSH is still controversial amongst labs and medical providers. Lab facilities consider the upper limits of normal to be between 4 and 5 (which is way too high!), while general endocrinologists agree that upper limit of normal is 2.5-3. Dr Shaw and I tend to follow a more integrative or functional medicine approach when it comes to a “normal thyroid range.” We agree that 0.4-2.4 is considered “normal”range for the TSH, but there is even more grey within this and following a patient’s symptoms trumps the numbers on the actual paper. It takes years of experience with treating these patients to become comfortable with “what is a normal TSH,” because every patient varies.
The TSH tends to go higher when the production of free T3 and free T4 are lower. If the output of free T4 and free T3 is low, the TSH is going to be higher. When the free T4 and free T3 are higher, the TSH will be lower as it does not need to stimulate the thyroid gland as much.
Free T3 and Free T4
Free T3 (known as Triiodothyronine) and free T4 (known as Thyroxine) are the two hormones produced by the thyroid gland. Free T4 is produced first and converts/changes into free T3. Free T3 is considered the “active” form and is dispersed out into the body so that all of our metabolic functions can occur (easier terms: to make us feel good and have all our systems up and running at their optimal levels).
If the TSH is high and free T3 and free T4 are low, this indicates a diagnosis of hypothyroidism. If the TSH is normal along with free T4, but free T3 is low there is problem with the conversion of T4 to T3. If the TSH is normal but free T4 and free T3 are borderline AND the patient is symptomatic, this is a special situation where the patient does have hypothyroidism but the TSH has not caught up.
Again, there are grey areas when interpreting these three labs together, but this is where a deep and understanding dialogue should occur between you and your primary care practitioner.
Thyroid antibodies are ordered to clarify if the hypothyroidism is coming from an autoimmune source. Hashimotos thyroid disease is the most common diagnosed thyroid disease in our country, but in the same breath the most under-diagnosed due to lack of testing.
Specific antibodies include: TPO antibodies (thyroid peroxidase antibodies) and TgAb (thyroglobulin antibodies). If there is elevation in TPO antibodies and/or TgAb, we have an autoimmune diagnosis of hypothyroid. Once positive, we continue to use them to evaluate if there is improvement in the thyroid function and to help us determine if we are on the right path to controlling the thyroid as best as possible.
Reverse T3 is definitely the hormone most commonly NOT checked by primary care practitioners. It remains controversial in the conventional medicine world, and should be discussed during your dialogue with your primary care practitioner.
When your body wants to hold on to free T3 rather than use it as an active form, it transfers it to an inactive form. This tends to happen when you’re under tons of stress, undernourished, or are sick with a fever. If the TSH and free T4 are normal but the free T3 is low on lab results, the reverse T3 may be elevated. This would indicate that the free T3 is being converted to its inactive form. We feel it is beneficial to check the reverse T3 when patients are symptomatic, as the TSH and free T4 might not be “low” in these instances.
Additional labs to consider…..
Hypothyroidism can also be caused by deficiencies in zinc, selenium, iron, vitamin D, and vitamin B12. Levels of these minerals and vitamins should therefore be assessed when hypothyroidism is diagnosed. Gluten intolerance, environmental exposures, and heavy metal exposures should be considered as well, but this topic is a whole other blog post in itself.
How to approach your practitioner with your concerns and suggestions
Now, here is the sticky icky part of this blog post. We are living in a much different world than we were 20 years ago. Medicine is changing along with everything else, and how practitioners are approaching assessing, diagnosing, and treating their patients is constantly evolving. We (conventionally trained practitioners) want to believe that ALL providers have an open mind. But there are the few that are completely resistant to listening to what their patients are saying and instead have a “it’s my way or the highway” mentality. You should be able to have an open and honest conversation with your practitioner, not only about your symptoms but the research you have found surrounding them.
I hope you found this blog post informative and now have a little more knowledge in regards to the thyroid and the testing that comes along with it. If you have any questions or suggestions regarding this blog post or any of the previous for that matter don’t hesitate to contact us via social media (Instagram, Facebook or Twitter) or email firstname.lastname@example.org
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