I get asked all the time, “is hypothyroidism an autoimmune disease?” This is one of many areas that conventional medicine gets wrong. As a former thyroid and autoimmune patient, as well as being a medical doctor, thyroid disease and autoimmunity is a topic dear to my heart. So, is hypothyroidism an autoimmune disease? If you’re speaking about hypothyroidism generally, it’s not an autoimmune disease. However, Hashimoto’s thyroiditis is a common autoimmune disease and is the leading cause of hypothyroidism.
As I explain in my New York Times best-seller, “The Thyroid Connection,” not all patients who have Hashimoto’s have hypothyroidism, and not all hypothyroidism patients have Hashimoto’s. If that seems a bit confusing, don’t worry. I’m going to explain it all in this article, as well as answer the question, “is hypothyroidism an autoimmune disease.” Before I get into that, I’m going to tell you about my story with autoimmune thyroid disease.
Conventional Medicine Failed Me
Your thyroid can become either overactive (hyperthyroidism) or underactive (hypothyroidism). I was diagnosed with Grave’s disease while I was in medical school. Graves disease is an autoimmune disease that causes the thyroid to overproduce thyroid hormones, also known as hyperthyroidism.
An estimated 20 million people in the U.S. have some form of thyroid disease. Up to 60% of those people don’t even know they have one. What’s even more alarming is that women are 5 to 8 times more likely than men to develop thyroid disorders. While those statistics can seem frightening, it doesn’t have to be this way.
Conventional medicine gave me three options: use radioactive iodine to ablate (blow up) my thyroid, take a medication known as propylthiouracil (PTU) that had awful side effects, or have my thyroid surgically removed.
I initially decided to take Propylthiouracil (PTU). It nearly cost me my life and medical school. It devastated my liver, causing me to be confined to bed rest until my liver was healed. The awful side effects were too harsh so I ended up having my thyroid ablated, a decision I still regret to this day. If I would have known then what I know now, I would have made a different choice. Conventional medicine failed me, and it is my mission not to have it fail you, too.
I’m going to give you the tools to take back your health and tell you about my proven method to reverse your autoimmunity. First, let’s talk more about whether or not hypothyroidism is an autoimmune disease.
Is Hypothyroidism an Autoimmune Disease?
The definition of an autoimmune disease is when your immune system can’t tell the difference between your own cells and foreign invaders. Hypothyroidism is when your thyroid doesn’t produce enough thyroid hormones.
So, generally speaking, hypothyroidism is not an autoimmune disease. However, stress, chronic inflammation, a lousy diet, and toxic exposure can cause your immune system to go rogue and attack healthy cells, including your thyroid. Let’s go a bit deeper.
What is Hypothyroidism?
Hypothyroidism is the most common form of thyroid disease and affects nearly 5 out of every 100 Americans ages 12 years or older.1
Your thyroid can not produce enough thyroid hormone due to a malfunctioning pituitary gland. Your pituitary gland sends thyroid-stimulating hormone (TSH) to your thyroid. There are times when your TSH levels are normal, yet the thyroid doesn’t produce enough T4 and T3.
The hypothalamus, which is responsible for managing hunger, thirst, sleep, hormones, and body temperature, among other important functions, also 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, then releases Thyroid Stimulating Hormone (TSH) directly to the thyroid.
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 the 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.
Does Hypothyroidism Weaken the Immune System?
As I mentioned, the common cause of underactive thyroid is Hashimoto’s, which occurs when your immune system attacks your thyroid. When your thyroid is under constant attack, it cannot make enough thyroid hormones. The good news is that an underactive thyroid does not weaken your immune system.2 However, if your immune system is constantly in overdrive it can become less effective against real foreign invaders. That’s why it’s important to address the root cause of your underactive thyroid.
Causes of Hypothyroidism
One of the most common causes of hypothyroidism is Hashimoto’s thyroiditis. Hashimoto’s causes inflammation of the thyroid, which leads to an underactive thyroid gland.3
Conventional medicine would lead that once you have an autoimmune disease, you have it for the rest of your life. As a functional medicine doctor, I’m here to tell you that’s not the case. There are five root causes of autoimmune disease:
Because these root causes can be addressed through lifestyle and diet changes, you can reverse your Hashimoto’s. Other causes of hypothyroidism include damage to the pituitary gland caused by noncancerous tumors or a head injury or destruction of your thyroid gland.4
I’ve told you about hypothyroidism and Hashimoto’s and that you can have Hashimoto’s and not have hypothyroidism, and vice versa. You might be asking that if Hashimoto’s is an autoimmune disease, would an underactive thyroid eventually turn into Hashimoto’s? Well, it’s not that simple. Let’s talk more about Hashimoto’s.
What is Hashimoto’s Thyroiditis?
Dr. Kakaru Hashimoto discovered the autoimmune disease Hashimoto’s thyroiditis in 1912. As I’ve mentioned, Hashimoto’s causes your immune system to mistake your thyroid gland as a foreign invader.
Your thyroid produces an enzyme called thyroid peroxidase (TPO), which is a vital component for producing thyroid hormones. When you have Hashimoto’s thyroiditis, your immune system creates TPO antibodies that are designed to attack the thyroid in a mistaken attempt to fight off what it believes to be a threat.
Signs of Hashimoto’s
If your thyroid isn’t producing enough thyroid hormone, it causes your metabolism rate to decline. This can lead to a myriad of symptoms, including:5
If you are experiencing any of these signs, then I recommend having your doctor order a thyroid test.
Testing Your Thyroid Levels
Conventional medicine will only check your TSH levels., To get a clear picture of your thyroid health, ask your doctor to test FT4, FT3, RT3, and antibodies for optimal levels. I’ve outlined the optimal levels of each hormone:
- TSH Levels: 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 relates 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 the labs listed above and use optimal reference ranges while working with you to restore your thyroid function. If that is not the case, you can use LetsGet Checked‘s complete thyroid panel and take your results back to your physician.
The Functional Medicine Approach to Hypothyroidism
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®.
In my New York Times bestseller, “The Thyroid Connection” I talk about this proven method that I’ve used with thousands of patients and seen amazing results in my decades of experience as a physician.
To support optimal thyroid function while following The Myers Way®, I recommend adding The Myers Way® Multivitamin. I formulated this multivitamin with thyroid health in mind. It is packed with optimal levels of micronutrients in bioavailable 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 balanced stress response.
As a former thyroid patient, I understand that it can feel overwhelming. I’ve made it my mission to empower you to achieve optimal health and give you the tools you need. Is hypothyroidism an autoimmune disease? When it occurs as Hoshimoto’s it is an autoimmune disease. The good news is that because it is an autoimmune disease, you have the power to reverse your condition using the tools I just gave you!
- Hypothyroidism (Underactive Thyroid). National Institute of Diabetes and Digestive and Kidney Diseases. 2021.
- Thyroid disease and coronavirus (Covid-19). British Thyroid Foundation. 2020.
- Hypothyroidism: An Overview. Cleveland Clinic. 2022.
- Understanding Pituitary Disorders. OHSU Brain Institute. 2021.
- Hashimoto's Disease. Mayo Clinic. 2022.