Hypothyroidism (low thyroid function) is a common condition affecting millions of women! It can cause issues like low energy, thinning hair or hair loss, weight gain (despite your best efforts), constipation, period problems, infertility, joint pain, brain fog, mood imbalances, dry skin, and more! But did you know there are actually 6 types of hypothyroidism?

And standard conventional testing can miss FIVE of them?!

You deserve better! So read on to learn more about the 6 types of hypothyroidism.

#1: Pituitary Dysfunction (Secondary Hypothyroidism)

Your pituitary is a gland in your brain that talks to your thyroid and plays a big role in controlling how much thyroid hormone you make.

To put it simply, when thyroid hormone is too low, your pituitary will (*should*) speak up by increasing the secretion of thyroid stimulating hormone (TSH). Higher levels of TSH tells your thyroid to make more thyroid hormone.

But sometimes, there are imbalances going on that affect your pituitary function. And when this happens, your pituitary may not raise TSH in response to low thyroid hormone. This is called “secondary hypothyroidism” because the issue isn’t really with your thyroid. The problem is that your pituitary is asleep on the job.

There are three main scenarios that can disrupt pituitary function and result in low thyroid hormone:

1. High levels of cortisol: this can be caused by stress, blood sugar imbalances (and not just pre-diabetes or diabetes), chronic or stealth (hidden) infections, inflammation (from a variety of sources), and more. Over time, high levels of cortisol can reduce pituitary function, which can then affect how your thyroid is behaving.
2. Serotonin and dopamine deficiencies: this can be caused by blood sugar dysregulation, neuroinflammation (inflammation impacting the brain), nutritional deficiencies like magnesium and vitamin B6, and iron dysregulation (which can look like iron deficiency but isn’t). You need healthy neurotransmitter levels to stimulate the pituitary gland (and healthy pituitary function to stimulate your thyroid).
3. Neuroinflammation: this can stem from a variety of sources, including leaky gut (yep, your gut affects your brain!), but the bottom line is that inflammation in your brain can have a major impact on pituitary function. The #1 clue you have neuroinflammation is brain fog!

This type of hypothyroidism won’t get picked up on by standard conventional testing, unless the TSH is below the normal range. And unfortunately, the normal reference range for TSH is so wide, this pattern is likely to go unnoticed unless your doctor is also testing thyroid hormone levels (total T4, free T4, total T3, and free T3). Learn more about thyroid testing here.

#2: Primary Hypothyroidism

This form of hypothyroidism occurs when the breakdown is at the level of the thyroid gland. In this scenario, your pituitary gland is doing its job, and you will see a high TSH in response to the low thyroid hormones. The problem, however, is that your thyroid isn’t producing adequate levels of thyroid hormone, even though your brain is telling it to.

This type of hypothyroidism will usually be identified by standard conventional testing, which focuses on measuring TSH.

#3: Autoimmune Thyroid Dysfunction / Hashimoto’s

With autoimmune hypothyroidism, the problem isn’t actually your thyroid gland—it’s your IMMUNE SYSTEM! 

In this scenario, your immune system ends up targeting the tissues of your thyroid gland, and this attack causes problems with your thyroid function and thyroid hormone levels.

Standard conventional testing does NOT include routine testing for thyroid antibodies because it doesn’t change how conventional doctors treat the condition!

BUT, knowing if your thyroid dysfunction is autoimmune in nature actually makes a BIG difference because there is a LOT you can do to balance immune function and put autoimmunity into remission—and therefore stop the ongoing destruction of your thyroid gland!!

It’s important to keep in mind that you can actually have elevated thyroid antibodies long before clinical disease shows up! 

In other words, you can be dealing with autoimmunity for several months—or even years—before the standard conventional testing comes back abnormal. And if you don’t know that’s going on, then you are missing a GOLDEN OPPORTUNITY to halt the autoimmune process before it starts affecting your thyroid to the point that your labs are abnormal.

Autoimmunity is a HUGE topic, but the main takeaway is this: YOUR BODY IS NOT “CONFUSED.” (It’s way more brilliant than that!) 

With thyroid autoimmunity, your immune system is trying to deal with a REAL issue (food sensitivities, infections, trauma, toxins, etc.), and your thyroid is getting caught up in the crossfire. Addressing the root issue(s) allows you to put the autoimmune process into remission, and this is absolutely worth your time and effort! Read more about the 7 root causes of illness here.

#4: Transportation Issue

Thyroid hormones ride around on proteins while traveling through your bloodstream. You can think of these binding proteins as busses that transport your thyroid hormones all over your body.

Your body can’t use thyroid hormone when it’s on the bus. Thyroid hormone has to get OFF the bus to be useable.

This means that low or high levels of these thyroid binding proteins will impact how much thyroid hormone is available for your body to use!

When thyroid binding protein levels go up, more thyroid hormone will be on busses, and less thyroid hormone will be available to interact with your cells.

When thyroid binding protein levels go down, there are less busses, so more thyroid hormone will be available to your cells. 

Binding protein levels can be affected by liver function and detox, blood sugar regulation and insulin surges, excess fat cells, estrogen and testosterone levels (this is one reason why birth control and hormone replacement therapy should ONLY be used when necessary AND only until the root causes of your hormone imbalances are addressed), and more.

Standard conventional testing misses this issue.

#5: Conversion Issue

Your thyroid primarily makes T4 (thyroxine), which is the inactive form of thyroid hormone. As your body needs T3 (triiodothyronine)—the active form of thyroid hormone—it will convert T4 into T3. 

This T4 to T3 conversion primarily happens in your liver, with about 20% happening in your gut. Your kidneys also convert some T4 into T3. 

Which means that liver dysfunction, gut issues, and suboptimal kidney health can impact how much active thyroid hormone you have! Inflammation and increased cortisol also interferes with the conversion of T4 into T3.

This means that you can be making adequate levels of T4, but if you aren’t converting T4 into T3 efficiently, you can still have symptoms of hypothyroidism! 

Conventional testing misses T4 —> T3 conversion issues.

#6: Receptor Site Resistance

It’s not enough to make adequate thyroid hormone. Your cells also have to be able to USE it! And this is only possible when thyroid hormone can attach to thyroid hormone receptors.

Increased cortisol, inflammation, low vitamin A, methylation issues, and more can interfere with receptor sites and disrupt the ability for thyroid hormone to attach to those receptors. 

Which means you can have normal levels of T4, and you can be converting T4 into T3 at an appropriate rate, but if that thyroid hormone can’t attach to your thyroid hormone receptors, you can still have symptoms of hypothyroidism!

There isn’t really a way to test for receptor site issues, but taking a good history, running a comprehensive thyroid panel, checking inflammatory markers, and exploring adrenal health and methylation can help to reveal this issue.

GET A COMPREHENSIVE THYROID PANEL!

As you can see, there are multiple ways that thyroid function can break down in the body, which is why there are 6 types of hypothyroidism! It’s also why I recommend that every woman get a comprehensive thyroid panel every year!

Read more about the thyroid testing I suggest here.

And be sure to have a provider on your team who’s aware of these 6 types of hypothyroidism AND trained in naturopathic or functional medicine, so they actually understand the importance of those additional thyroid markers and what to do with the results! Including how to interpret them from a functional perspective so that imbalances can be spotted and addressed BEFORE your labs are abnormal!

Want personalized guidance? Learn how my approach can help you optimize thyroid function and overall health here.