The Adrenal-Thyroid Connection

I’m going to be honest here: Stress is a given in our lives. I know I can’t avoid it and, while I’m not much of a gambler, I’d be willing to bet you can’t either. Yet, whether you have Hashimoto’s or hypothyroidism, Graves or hyperthyroidism, or you haven’t been diagnosed yet, stress and your adrenals play a huge role in your thyroid health.

Fortunately, that doesn’t mean there’s nothing we can do about it. The key is to understand the adrenal-thyroid connection, how stress affects thyroid function, and how to relieve it!

How Chronic Stress Impacts Thyroid Function

You probably know your adrenal glands for producing adrenaline and managing your fight or flight response. However, did you know that, as part of your endocrine system, they also produce hormones that impact major metabolic processes, just like your thyroid does? The hormones produced by your adrenal glands help to regulate blood pressure, electrolyte balance, blood sugar, immune response, digestion, and more.¹

When you experience stress, be it emotional, mental, or physical, your hypothalamus sends a signal to your pituitary gland. Your pituitary gland signals your adrenal glands to produce and release a series of stress hormones, including cortisol.²

Once a stressor triggers this cascade of hormones, cortisol and your other stress hormones redirect your body’s normal functions to essentially ignore anything that is not necessary for overcoming the stressor in front of you. This means that functions such as digestion, immune response, and yes, thyroid hormone production and distribution, are temporarily put on hold or slowed down until the stress has passed. Ideally, the stress passes quickly, your body returns to normal, and everything runs smoothly once more.

Unfortunately, due to our hectic lifestyles, many of us experience chronic stress, either because our stress does not end quickly or it is quickly followed by another stressor. This state of chronic stress puts your adrenals on overdrive for extended periods of time, continuously flooding your body with cortisol until your adrenals can no longer keep up with the constant demand for more and more stress hormones, leaving you in a state of adrenal fatigue. This flooding and eventual plummeting of stress hormones have many negative impacts on the thyroid.

Slowed Thyroid Hormone Production

Cortisol functions in a negative feedback loop with the hypothalamus and pituitary gland. Once it enters your bloodstream, its presence signals to your hypothalamus and pituitary gland to slow down so that they don’t trigger any additional stress hormones. These organs also regulate thyroid hormone production, so that slows down as well.

Reduced T4 to T3 Conversion

Stress hormones affect the enzymes that convert T4 to  T3.  Remember that Free T3 (FT3) is the active form of the hormone that I like to think of as the ‘gas.’ Reverse T3 (RT3) is the inactive form of the hormone that I like to think of as the ‘brakes.’  When stress is high we convert more of our T3 into RT3 rather than FT3. This imbalance essentially puts the brakes on all of your metabolic processes, slowing them down and causing hypothyroid symptoms.

Thyroid Hormone Resistance

Also released in the stress response are inflammatory immune cells called cytokines, which make thyroid receptors less sensitive to thyroid hormones. This means that even if you’re taking thyroid medication and your thyroid hormone levels are normal, you can still be suffering from underactive thyroid symptoms.

Shortage of Unbound Thyroid Hormone

Prolonged cortisol elevation can cause excess estrogen to accumulate.³ This extra estrogen increases levels of thyroid-binding globulin (TBG), which is the protein that allows your thyroid hormones to travel through your bloodstream. When thyroid hormones are attached to TBG they remain inactive, so T4 can’t be stored in your tissues or converted to Free T3.

Suppressed Immune System

While your body is in stress mode your immune system is suppressed. Partially so that your body can focus fully on overcoming the stressor, and partially because stress causes inflammation. Your immune system slows down to prevent a state of chronic inflammation. As I explain in my book, The Thyroid Connection, a suppressed immune system can trigger latent viral infections, some of which can trigger autoimmune thyroid disease.

Furthermore, if you experience multiple episodes of chronic stress, causing your immune system to rev up and slow down repeatedly, you are at greater risk of your immune system overreacting and triggering an autoimmune response.

Weakened Gut Barrier

As part of suppressing your immune system, cortisol weakens your immune system’s primary barriers—the blood-brain barrier, lungs, and gut barrier.⁴ As we know from Part II of this series, a weakened gut barrier leads to leaky gut, which sets you on the path toward autoimmune disease by releasing gluten and dairy, among other things into your bloodstream. These can trigger attacks on your thyroid via molecular mimicry.

How to Best Test for Adrenal Fatigue

As you can see, your adrenal function plays a huge role in the effectiveness of your thyroid hormones. It is very important to determine if adrenal stress is an underlying cause of your thyroid dysfunction. That way you can treat them side by side.

In fact, many patients with adrenal-related thyroid problems who are put on thyroid medication without adrenal support initially get worse. They can experience a racing heart or shaking hands as their body is forced into overdrive from the sudden rush of thyroid hormones.

Conventional doctors typically rely on a blood test to measure cortisol levels, but your stress hormone levels fluctuate significantly throughout the day. That means the one-time test does not provide nuanced results. If you want to test your cortisol levels at home, I recommend using the home cortisol test from LetsGetChecked. It measures adrenal performance or stress through a simple finger prick blood test. The results are available online so you can share them with your functional medicine doctor. 

The Myers Way® Adrenal Fatigue Test

If you are unable to use a saliva test or do not feel that formal testing is necessary, I have a basic symptoms checklist test in both of my books, The Thyroid Solution and The Autoimmune Solution, that will give you an idea of your degree of adrenal fatigue. You can also download a PDF version in the link below.

How to Reduce Stress and Support Your Adrenals

The best way to support your adrenals and accompanying thyroid problems long-term is to learn to manage your stress. Realistically speaking, there will always be stress in your life, but learning the tools and routines to leave a stressful situation behind after it’s over, instead of carrying it around with you, will reduce the physical effects of chronic stress.⁵

Stress-Relieving Tools to Support Your Adrenals

Here are two of my favorite ways to reduce stress:

• Infrared Sauna Therapy – Spending time in an infrared sauna has many health benefits, including stress relief and detoxification. I have one in my home, and you can also receive treatments from natural spas that house their own.
• A relaxing hot bath – I love winding down with a relaxing hot bath in the evening. For a little extra pampering and relaxation, check out this recipe for a DIY Calming Lavender Body Oil Scrub

Helpful Supplements for Adrenal-Thyroid Health

1. Adaptogenic herbs help the body adapt and cope with stress. My go-to supplement to support the adrenal gland contains Rhodiola rosea, Panax ginseng, and a number of other herbal extracts. I carry The Myers Way® Adrenal Support, in my store to promote a healthy stress response.
2. All B vitamins are critical for the chemical processes within the adrenal glands, which makes my multivitamin ideal for adrenal support. It contains all 8 B vitamins in their pre-methylated forms.
3. For added adrenal support, you can also take Omega-3 fatty acids, vitamin C, and magnesium.

If you are curious about your own adrenal health or would like further assistance in combatting your adrenal fatigue, I highly recommend seeking a Functional Medicine practitioner in your area.

For more information, check out my interview with James Gordon on the impact of stress and trauma on thyroid health.