The relationship between the adrenal glands and the thyroid is a crucial aspect of the body’s endocrine system, as both are integral parts of maintaining overall hormonal balance and managing stress responses and metabolism. While “adrenal fatigue” is often cited in alternative medicine to describe a state where prolonged stress leads to inadequate adrenal function, it is not an officially recognized medical diagnosis. Many conventional doctors are quick to blow off this syndrome. However, the symptoms of chronic stress and overwhelmed adrenal glands can impact thyroid function in many ways. In today’s article, I’ll review the connection between adrenal fatigue and the thyroid gland, some common causes of adrenal fatigue, and how high and low cortisol levels affect the thyroid. Lastly, I will make sure to highlight the different testing needed to uncover this adrenal-thyroid connection.

Be On the Lookout For Adrenal Fatigue If You Have Thyroid Disease

If you are taking thyroid medications and you find yourself still struggling with fatigue, weight gain, immune system problems, insomnia, brain fog, or if your has to continue increasing your thyroid medication because they can’t dial in your thyroid medication dosage,  you should be on the alert for Adrenal Fatigue Syndrome. Not only can your adrenal affect thyroid function but thyroid function can also affect adrenal gland function. This is why when I work with a patient who has either of these conditions, I am always evaluating both the thyroid and adrenal glands. Let’s take a look at this Thyroid Adrenal connection

How Thyroid Disease Impacts Adrenal Function:

Both hypothyroidism and hyperthyroidism affect adrenal function. Let’s review this relationship.

Hypothyroidism’s Effects: Low thyroid hormone levels (low T3 or Low T4) can result in decreased metabolic rate, slower clearance of cortisol from the bloodstream, and increased sensitivity to stress, potentially burdening the adrenal glands over time.

Hyperthyroidism’s Effects: An overactive thyroid with too much T3 or T4 thyroid hormone can lead to higher metabolic demand, increasing nutrient requirements, and potentially stressing the adrenal glands, forcing them to work harder.

How Cortisol Affects Thyroid Function

Both high and low cortisol affect your thyroid. Here are a few ways, studies demonstrate the impact of cortisol on thyroid function.

1. 1. Both High and Low cortisol can reduce or suppress the Hypothalamic-Pituitary-Axis (HPA) (*),(*)
   2. Cortisol can lower your Thyroid Stimulating Hormone (TSH) levels leading to reduced T4 and T3 production.
   3. Thyroid Receptor Downregulation- Thyroid receptors become dull. Excessive cortisol may also affect the sensitivity of cells to thyroid hormones, potentially leading to symptoms of hypothyroidism such as fatigue, weight gain, and depression.(*)
   4. High Cortisol Affects Your Thyroid Gland by reducing the conversion of T4 to T3
   5. High Cortisol Affects Your Thyroid Gland by increasing the conversion of T4 to Reverse T3 (rT3).
   6. Cortisol helps regulate glucose production and utilization. An important relationship also exists between your thyroid and blood sugar.

Common Causes Of Adrenal Fatigue/Chronic Fatigue Syndrome

1. Chronic Stress: The primary theory behind adrenal fatigue is that prolonged exposure to stress can overstimulate the adrenal glands, causing them to eventually produce inadequate levels of cortisol, leading to symptoms like Chronic fatigue, irritability, and difficulty concentrating.

2. Lack of Sleep: Consistently getting insufficient or poor-quality sleep can place additional strain on the body’s stress response system, which may lead to persistent feelings of fatigue and overall decreased well-being. You can read this article on “Why the adrenal glands cause sleep disturbances.”

3. Poor Diet: A diet lacking essential nutrients can affect various bodily functions, including hormone production and stress management, potentially contributing to feelings of fatigue. Check out this article for more information on adrenal fatigue diet and what to eat. You can also watch this video on some of the dietary changes you should make.

4. Overwork and Lifestyle Factors: Long working hours, insufficient time for relaxation, and lack of self-care can all contribute to mental and physical fatigue.

5. Emotional Stress: Situations involving emotional turmoil, such as relationship issues or persistent worry, can overtax the body’s stress-response system.

6. Caffeine and Stimulants: Caffeine can stimulate your adrenal glands to produce higher amounts of cortisol. This High Cortisol Affects Your Thyroid Gland. Stimulants including caffeine and energy drinks to deal with fatigue can exacerbate stress on the body and disrupt natural sleep patterns.

7. Infections or Illnesses: Recurrent or chronic infections and illnesses can contribute to ongoing fatigue and stress on the body’s systems.

Testing For Adrenal Fatigue

There are several ways to test for Adrenal fatigue. There are pros and cons to each. Your Certified Functional Medicine Doctor can help determine the best way to test your adrenal glands based on your health history.

1. Blood Cortisol Testing

This is the most common method for assessing cortisol levels and involves drawing blood, typically from a vein in the arm.

Timing: Cortisol levels vary significantly throughout the day, usually peaking in the early morning and reaching their lowest in the evening. Therefore, healthcare providers often recommend performing a morning blood cortisol test, usually between 7 a.m. and 9 a.m., when cortisol levels are at their highest.

Utility: Blood tests can give a snapshot of cortisol at one specific point in time and are often used to screen for conditions like Cushing’s syndrome (characterized by excess cortisol) or Addison’s disease (characterized by insufficient cortisol).

Advantages: Blood tests are straightforward and can be easily done in a clinical setting.

Disadvantages: They only provide information about cortisol levels at the exact time of the blood draw and can be influenced by the stress associated with the blood draw process itself.

2. Saliva Cortisol Testing

Process: Saliva cortisol testing involve collecting a saliva sample, usually by spitting into a tube. These tests are particularly useful for assessing cortisol rhythms over a 24-hour period.

Timing: Saliva samples can be collected at multiple times throughout the day (e.g., morning, noon, evening, and night) to provide a profile of how cortisol levels change over the day.

Utility: Saliva tests are valuable for studying daily cortisol rhythms and can help in diagnosing disorders like adrenal fatigue if clinically suspected.

Advantages: Non-invasive, easy to collect multiple samples at different times of the day, can be done at home, and reflects the free (biologically active) cortisol. Another advantage is that cortisol testing throughout the day can help pinpoint when your adrenal glands are struggling the most, it can also help explain insomnia in some patients.

Disadvantages: Can be less accurate if the sample is contaminated (e.g., food particles), bleeding gums, or caffeine consumption. Testing is done through specialty labs as not all labs are equipped to process these tests.

3.  24-hour Urine Test:

A 24-hour urine cortisol test like the DUTCH test, measures the total amount of cortisol and the cortisol metabolites excreted in urine over a day, providing an average daily cortisol level production, as well as an understanding of how cortisol is breaking down.

Disadvantages- Since this test measures urine, dehydration will cause urine to be concentrated skewing test results. On the other hand, if you consume too much water, your urine will be diluted and once again you may have skewed test results.

What Would Happen If I Have Adrenal Fatigue With Hypothyroidism?

As I have reviewed throughout this article, If someone has both adrenal gland issues and hypothyroidism, you can expect the symptoms you see below to be magnified. You will also find it almost impossible to have any long-standing improvement in either condition if both are not treated at the same time.

1. Fatigue and Low Energy: Both adrenal issues and hypothyroidism can cause significant fatigue. When present together, the fatigue can be more profound, and typical daily activities may become challenging.

2. Hormonal Interplay: The thyroid and adrenal glands interact within the endocrine system. Adrenal gland dysfunction can affect how tissues respond to thyroid hormones. Before starting thyroid hormone replacement therapy, it’s important to assess adrenal function, as inadequate adrenal hormone levels can lead to complications when thyroid medications are introduced.

3. Stress Response: As mentioned above, the Adrenals help the body manage stress. If they are not functioning well, and this is combined with hypothyroid-induced low energy, handling stress may become increasingly difficult, leading to a vicious cycle of worsening symptoms.

4. Metabolic Effects: Both adrenal insufficiency and hypothyroidism can slow down metabolism, leading to symptoms like weight gain, cold intolerance, and constipation. The combination can intensify these effects.

5. Mental Health: Both conditions can impact mental health, contributing to symptoms of depression or anxiety. Proper diagnosis and management of these conditions are crucial in improving mood and mental clarity.

Practical Considerations

The relationship between the adrenal glands and the thyroid is a very real one that many practitioners overlook when working with patients who continue to struggle with thyroid disease despite thyroid hormone replacement.

Holistic Management: Given their interaction, addressing symptoms related to these glands often requires a comprehensive approach. Ensuring proper nutrition, managing stress, and maintaining a healthy lifestyle are key to supporting both adrenal and thyroid health.

Medical Assessment: A healthcare provider may examine levels of cortisol, TSH, T3, and T4, reverse T3 among other parameters, to assess both adrenal and thyroid function. Treatments from a functional medicine practitioner often include supplementation like DHEA, pregnenolone, Adaptogens, Vitamin C, B vitamins, lifestyle interventions, and stress-reduction strategies.

Together, these glands significantly influence each other’s function, and issues in one may exacerbate or cause problems in the other. Thus, understanding and managing them holistically is central to restoring and maintaining well-being.

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