Thyroid disease is a subject that hits close to home for me. I was diagnosed with Graves’ disease while I was in medical school.

Conventional medicine gave me three options: Take a medication known as propylthiouracil (PTU), which has really awful side effects; use radioactive iodine to ablate (blow up) my thyroid; or have my thyroid surgically removed. 

I eventually made the decision to have my thyroid ablated, a decision I regret to this day. I have since made it my mission to help those facing thyroid disease and other chronic illnesses reverse their thyroid disease and return to optimal health using functional medicine principles.

More than 12% of the U.S. population will develop a thyroid condition during their lifetime. An estimated 20 million Americans have some form of thyroid disease, and up to 60% of those people don’t even know they have thyroid disease. What’s even more alarming is that women are 5 to 8 times more likely than men to develop thyroid disease. 

While those statistics can seem frightening, it doesn’t have to be this way. I’ll explain what can go wrong with your thyroid, the symptoms of thyroid disease, and how to reverse your symptoms! Let’s start by taking an in-depth look at the role your thyroid plays in your body.

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How Your Thyroid Works

Think of your thyroid gland as your body’s power generator. It sends energy to every cell in your body through the hormones it produces. These hormones determine the energy level and reproduction of each cell, keeping your organs powered up and managing your overall metabolism. The process of creating, regulating, and delivering these hormones begins in your brain.

The hypothalamus, which is responsible for managing hunger, thirst, sleep, hormones, and body temperature, among other important functions, monitors the level of thyroid hormones present in your bloodstream. If it determines energy levels are low, it sends out Thyroid Releasing Hormone (TRH), to your pituitary gland. Your pituitary gland, a pea-sized gland at the base of your brain, releases Thyroid Stimulating Hormone (TSH) directly to the thyroid.

Thyroid Hormones

Your thyroid is then prompted to produce thyroid hormones using an amino acid called tyrosine and iodine. It converts the tyrosine into thyroglobulin and attaches between one and four iodine atoms, creating T1, T2, T3, and T4 respectively.

The primary output of your thyroid is T4, thyroglobulin plus four iodine atoms—a storage form of the hormone. It is circulated throughout the bloodstream and stored in tissues so it’s available when needed. A much smaller percentage of the hormones produced is T3, the active form of thyroid hormone. T2 and T1 make up an even smaller percentage, and although we now know T2 is involved in metabolism rate, researchers are still unsure of what role these two hormones play.

When each local area of your body determines that it needs active T3, it converts the storage T4 to active T3 using an enzyme called deiodinase. This enzyme strips one of the outside iodine atoms off of the T4, turning it into Free T3 (FT3). Your body also uses a portion of the T4 to create Reverse T3 (RT3). This is done by stripping away one of the inside iodine atoms, creating another inactive form of thyroid hormone that can attach to Free T3 receptors.

The T3 enters cell membranes with the help of cortisol and regulates how much energy your mitochondria produce. Your mitochondria are the “power plants” of your cells and there are trillions of them in your body. Free T3 acts as a gas pedal for the mitochondria, revving up power production. Reverse T3 acts as a brake pedal, slowing down the power.

These micro-level reactions are a part of your endocrine system and work to control important metabolic factors such as heart rate, fatigue, weight regulation, brain function, and more. When your thyroid isn’t functioning properly it can affect any or all of these separate systems, creating a wide array of symptoms that might seem unrelated yet can all be traced back to your thyroid.

Types of Thyroid Disease

So what happens when your thyroid isn’t working properly? There are two primary types of thyroid disease: hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid). Let’s take a closer look at both. 


The most common form of thyroid disease is hypothyroidism, which is when your thyroid is underactive and does not produce enough thyroid hormone. 

This can happen because your pituitary gland is malfunctioning and not sending enough TSH to your thyroid, or your TSH levels are normal, but your thyroid isn’t producing enough T4 and T3 to adequately fuel your cells. I’ll explain how you can read your thyroid test results and what tests are done to check thyroid function later. Let’s discuss what causes hypothyroidism. 

Causes of Hypothyroidism

One of the most common causes of hypothyroidism is Hashimoto’s Thyroiditis, an autoimmune disease where your immune system attacks your thyroid.1 Inflammation from Hashimoto’s disease often leads to an underactive thyroid gland. 

Conventional medicine would lead you to believe that once you have an autoimmune disease you must live with it for the rest of your life. Since I was trained in functional medicine, I believe there are five elements that are at the root cause of all autoimmune diseases: 

Because these root causes can be addressed through lifestyle and diet changes, you can reverse your Hashimoto’s! I will tell you how later. 

Another cause of hypothyroidism is the destruction of the thyroid gland or damage to the pituitary gland or hypothalamic.2 The most common cause of pituitary damage is noncancerous tumors. A head injury can also cause damage to the pituitary gland.  When the hypothalamus or pituitary gland is damaged, the production of TSH decreases.3 

Iodine deficiency or inflammation of the thyroid gland are less common causes of hypothyroidism.4

Now that you understand an underactive thyroid, let’s discuss what happens when your thyroid goes into overdrive. 


When thyroid hormones are too high, energy metabolism will speed up, causing the body to burn through nutrients too quickly. This can result in malnutrition and lead to a wide range of problems. In college, I was eating everything in sight and went from a size 4 to a size 0 in a matter of months. Trust me when I tell you that it was not healthy!

Causes of Hyperthyroidism

There can be many reasons for the thyroid to be overactive, but this commonly occurs as a result of an autoimmune condition, known as Graves’ disease.5 Normally, thyroid function is regulated by the pituitary gland, a tiny gland responsible for secreting TSH, which signals the thyroid to produce thyroid hormones T3 and T4. 

With Graves’ disease, an antibody known as thyrotropin receptor antibody (TRAb) can mimic pituitary hormones and completely override the system, causing an overactive thyroid. You can also develop Thyroid Peroxidase (TPO) antibodies or Antithyroglobulin antibodies. I personally did not have TRAb antibodies, I only had TPO antibodies.

Another form of hyperthyroidism is toxic multinodular goiter, which involves the growth of independently functioning nodules on the thyroid gland itself. These nodules are able to stimulate the thyroid without the use of TSH, thereby overriding the system and causing an overactive thyroid.

The Autoimmune Connection to Thyroid Disease

So here’s the thing: Conventional medicine is failing far too many people. And nowhere is this failure more evident than with thyroid disease.

Thyroid disease is one of the most underdiagnosed and improperly treated health conditions in the world. This should come as no surprise given conventional medicine’s “one-size-fits-all” approach that focuses on treating symptoms rather than getting to the root cause of your condition. Unfortunately, conventional doctors are still using this outdated model of dealing with autoimmunity, despite the ever-increasing need for real solutions in this area.

Most patients’ thyroid disease is triggered by an autoimmune condition. Autoimmune disease occurs when the immune system mistakenly attacks your own cells. Hashimoto’s disease (hypothyroidism) and Graves’ disease (hyperthyroidism) are both autoimmune diseases. 

Many doctors who suspect a patient has something wrong with their thyroid only check their thyroid hormone levels, which indicate if the patient has hypo- or hyperthyroidism. They will likely not determine if it is caused by an autoimmune disease. 

I highly recommend that any patient diagnosed with thyroid disease have their thyroid antibodies checked using blood tests for Thyroid Peroxidase Antibodies (TPOAb) and Thyroglobulin Antibodies (TgAb). This is crucial because once you have one autoimmune disease, you are 3 times more likely to develop another one. The good news is that if you know your thyroid disease is autoimmune-related, you can reverse it.  

Fortunately, these two blood tests are very accessible and inexpensive, and can even be run without a doctor ordering them. I’ll discuss more on that in just a second. First, let’s go over the signs you have hyper- or hypothyroidism.

Signs of Thyroid Disease

Signs of Thyroid Disease – Infographic – Amy Myers MD®Signs of Thyroid Disease - Infographic - Amy Myers MD® of Thyroid Disease – Infographic – Amy Myers MD®

Symptoms of Hypothyroidism

The underproduction of thyroid hormones leads to a decrease in the metabolic rate. This is reflected in the suppression of the various functions of the body leading to a myriad of symptoms that include:

  • Fatigue
  • Brain fog
  • Weight gain or inability to lose weight
  • Cold hands or feet
  • Hair loss
  • Constipation
  • Poor concentration
  • Infertility
  • Low libido
  • Depression
  • Decreased heart rate
  • Decreased body temperature

Symptoms of Hyperthyroidism

The overproduction of thyroid hormones leads to an increase in the metabolic rate. This leads to an increase in the upregulation of the activity of various tissues. As a result, the disease manifests itself via the following symptoms:

  • Rapid heart rate
  • Severe anxiety and panic attacks
  • Insomnia
  • Weight loss
  • Hair loss
  • Increased body temperature
  • Shakiness or tremors
  • Loose stool
  • Increased hunger

Testing for Thyroid Disease

One question I am most frequently asked is, “What are the most important thyroid tests to assess my thyroid’s function?” This, along with what the thyroid test results mean, are two of the most important topics to understand to determine if you truly have thyroid disease or not. And let me tell you, there is a lot of misinformation on the internet and in the conventional medicine world surrounding thyroid tests and thyroid test results.

Many doctors who suspect you have something wrong with your thyroid only check your Thyroid Stimulating Hormone (TSH) levels, which indicate if you have hypo- or hyperthyroidism. If you are lucky, your doctor will test your Free T4 levels to see if they are low on the storage form of thyroid hormones. While these tests do a great job to uncover the nature of your thyroid disease, they only tell you a small part of the story.

Thyroid Tests

To get a complete picture of a patient’s thyroid health and medical needs, I recommend a doctor order all six tests listed below. It’s important that the results are read for optimal levels, not “normal” levels. 

The Highs and Lows of Thyroid Test Results – Infographic – Amy Myers MD®The Highs and Lows of Thyroid Test Results - Infographic - Amy Myers MD® Highs and Lows of Thyroid Test Results – Infographic – Amy Myers MD®
  • TSH Levels: This test is based on the activity of the pituitary gland. A high TSH level indicates hypothyroidism whereas a low TSH level indicates hyperthyroidism. The optimal levels of TSH should be 1-2 UIU/ML or lower.
  • Free T4 (FT4): FT4 refers to the unbound T4 – i.e. the one found in the bloodstream. High FT4 levels indicate hyperthyroidism whereas low FT4 levels indicate hypothyroidism. Optimal FT4 levels should be values greater than 1.1 NG/DL.
  • Free T3 (FT3): High FT3 indicates hyperthyroidism whereas low FT3 indicates hypothyroidism. Optimal levels are values greater than 3.2 PG/ML.
  • Reverse T3 (RT3): High RT3 levels indicate that there’s a high conversion of T4 to RT3 instead of FT3. This is an indicator of hypothyroidism. The optimal level compares the ratio of RT3 to FT3 and that value should be less than 10:1.
  • Antibodies test (TPO – TgAb levels): Since the most common forms of thyroid disease are autoimmune diseases, detection of thyroid antibodies is essential to get an accurate result. There are two antibodies of concern: TPOAb and TgAb. TPOAb refers to the thyroid peroxidase antibodies that target the enzyme that mediates the iodination of thyroglobulin. TgAb refers to the antibodies that attack thyroglobulin. Optimal levels for both antibodies should either be negative or values lower than 4 IU/ML.

My sincere hope is that your doctor is willing to order all of the labs listed above and then use the optimal reference ranges while working with you to restore your thyroid function. However, if that is not the case, you can use LetsGetChecked home thyroid tests. You can do the test in the privacy of your own home and then discuss your results with your functional medicine doctor. 

How to Prevent or Reverse Thyroid Disease

Managing your thyroid levels through thyroid medication is only part of the process. The real work comes in identifying the underlying factors that caused your thyroid disease and making healthy lifestyle changes to remove them. I call this The Myers Way®

This proven approach is a lifestyle that relieves and reverses your symptoms of thyroid disease, helps you get off your harsh medication, and enables you to live a healthy, energetic, and pain-free life.

This approach rests on four pillars, each of which has been tested through extensive research and have seen amazing results with thousands of patients over my own years of practice as a physician and while empowering the world to achieve optimal health through Amy Myers MD®.

The Myers Way® starts by healing your gut. Once you’ve healed your gut, it’s time to make a lifestyle change by getting rid of gluten, grains, and legumes from your diet.

For many people, 80% of the healing occurs while addressing the first two pillars. If you haven’t seen a full reversal of your symptoms, you need to dig deeper and that means reducing your exposure to toxins. Once Pillar III is addressed, I turn to the next piece of the puzzle: underlying infections and stress

To support optimal thyroid function while following The Myers Way®, I recommend adding The Myers Way® Multivitamin to your supplement regimen. This specially-formulated multivitamin is jam-packed with micronutrients in the forms your body wants and the amounts your thyroid needs. With optimal levels of thyroid-supporting minerals such as zinc, selenium, and iodine, alongside antioxidants including vitamins C and E and other free radical scavengers, no other multivitamin on the market does more to support your thyroid!

To get the additional benefit of supporting your thyroid health and immune system function, I designed my Hashimoto’s Support Plus Kit that includes The Myers Way® Multivitamin, along with Adrenal Support and ZenAdapt to facilitate optimal cortisol levels and a balanced stress response. 

I personally lived with thyroid issues. I’ve spent my career perfecting the art of supporting thyroid health for myself and anyone who wants to achieve optimal health. I hope this information empowers you to take back your health!

Tyroid FAQs

What are the types of thyroid disease?

Hypothyroidism and Hyperthyroidism are the two primary types of thyroid disease.

What is the most common thyroid disease?

The most common form of thyroid disease is hypothyroidism, which is when your thyroid is underactive and does not produce enough thyroid hormone.

What does your thyroid do?

Think of your thyroid gland as your body’s power generator. It sends energy to every cell in your body through the hormones it produces. These hormones determine the energy level and reproduction of each cell, keeping your organs powered up and managing your overall metabolism.

Multivitamin bottle.

Article Sources

  1. Hashimoto's disease. Mayo Clinic. 2020.
  2. Hypothyroidism (primary). Birte Nygaard, MD, PhD. BMJ Clinical Evidence. 2010.
  3. Understanding Pituitary Disorders. Oregon Health & Science University. 2021.
  4. Physiology, Thyroid Hormone. Muhammad A. Shahid, Muhammad A. Ashraf, and Sandeep Sharma. NCBI. 2020.
  5. Hyperthyroidism. Simone De Leo, Sun Y Lee, and Lewis E Braverman. Lancet. 2016.