Difference between adrenal fatigue and hypothyroidism

Adrenal Fatigue vs. Low Thyroid: How to Tell the Difference

Dr. Jolene BrightenPublished: Last Reviewed: Adrenal, Thyroid Leave a Comment

Hands up if this sounds familiar: You feel exhausted, but you can't sleep. Your weight is creeping up, but you don't have the energy to work out or cook. You're irritable and anxious, and you’re noticing more hair on the bathroom floor. It could be adrenal fatigue or low thyroid or… both. But how can you tell the difference?

Adrenal fatigue and low thyroid conditions can cause similar symptoms—but there are significant differences too. Both can be frustrating and seriously disrupt quality of life. But there is hope, and you can feel better and enjoy your life again! The trick is getting the right support, and that starts by narrowing down exactly what's happening in your body.

In this article, I'll teach you how to spot the differences between adrenal fatigue (and why this isn't exactly the correct term) and hypothyroid, the signs and symptoms of both, and how they are diagnosed, so you can get the help you need to feel like yourself again.

How are adrenal fatigue and low thyroid different?

It's common for people to confuse adrenal fatigue and low thyroid, as both conditions can lead to exhaustion, weight gain, and other symptoms. They also primarily affect women—women are 5 to 8 times more likely to have hypothyroidism than men. However, there are some critical ways in which they differ.

Adrenal fatigue is a condition that occurs when the adrenal glands, which produce stress hormones like cortisol, are sent the signal to stop producing as much cortisol or when the body creates proteins to bind it (more on this soon). On the other hand, low thyroid is when the thyroid gland doesn't produce thyroid hormone. The causes and treatments are very different (as I will discuss below).

Adrenal Fatigue AKA HPA-Axis Dysregulation

Let's take a step back and look at the definition of each. Adrenal fatigue isn't an actual diagnosis, but it's what people commonly name the constellation of symptoms that occur with hypothalamic-pituitary-adrenal axis (HPA-axis) dysregulation. Since so many people know it as adrenal fatigue, I'll use that phrase throughout the article with the understanding that I really mean HPA-axis dysregulation.

The HPA axis is a complex communication system between the hypothalamus, pituitary gland, adrenal glands, and adrenal hormones. It controls the stress response in our body. When we experience stress, the hypothalamus signals the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then signals the adrenal glands to release cortisol. Cortisol is sometimes called the “stress hormone” because it helps us respond to physical, emotional, or mental stress.

Cortisol is helpful short-term, but when we experience chronic stress, the adrenal glands are cranking out stress hormones for longer than what they were designed to do. With HPA dysregulation, the brain and adrenal communication is thrown off, which can result in feeling “wired and tired” or just flat out exhausted.

In addition, in an attempt to protect the body from the pro-aging effect of cortisol, the body will produce a binding protein called cortisol binding globulin (CBG). CBG grabs onto cortisol so that it can not stimulate the cells in the body.

Low Thyroid AKA Hypothyroid 

Low thyroid, or hypothyroid, also shows up as fatigue, but it's because the thyroid isn't functioning optimally. Your thyroid is like the body's metabolic thermostat, and it controls metabolism, weight, temperature, and heart rate. It also plays a major role in fertility and your menstrual cycle. With hypothyroid, you either don't make enough thyroid hormones to meet the body's needs (primary hypothyroidism), or you can't convert the available thyroid hormone to the active form.

The primary cause of hypothyroidism for most women is Hashimotos. In this autoimmune condition, the body mistakenly attacks its own thyroid tissues. But people can have hypothyroid for other reasons or even subclinical hypothyroid, which is an early form. With subclinical hypothyroidism, most labs technically fall within normal limits, but you can still have symptoms.

Both adrenal fatigue and hypothyroidism benefit from lifestyle changes like diet, supplements, stress management, and sleep, but other treatments differ. Hypothyroidism may require medication to get the thyroid hormone levels back to normal. At the same time, adrenal fatigue can often be resolved without medication (but there are supportive supplements).

If you are wondering if you have either, it's essential to consult with a doctor or other healthcare professional. With proper diagnosis and treatment, you and your doctor can manage both conditions effectively.

@drjolenebrighten Low thyroid hormone could be the cause of your period woes! #thyroid #thyroidproblems #thyroidhealth #hypothyroidism #hormones #hormonas #hormoneimbalanceprobs #hormoneimbalance #hormoneimbalances #periodprobs #periodproblems #periodproblemsbelike #casatiktok #latinxcreatives ♬ Say So (Instrumental Version) [Originally Performed by Doja Cat] – Elliot Van Coup

Adrenal Fatigue (HPA-axis Dysregulation) vs. Adrenal Insufficiency

It's important not to confuse HPA-axis dysregulation with adrenal insufficiency because they are very different conditions. Adrenal insufficiency is also called Addison's Disease. It's a serious, rare autoimmune condition that destroys the adrenal glands.

With HPA-axis dysregulation, there is no physical damage to the adrenals; it's just that the adrenals are not functioning optimally or the cortisol they are producing isn’t being used by the body.

If your adrenals need a little TLC, I designed the Optimal Adrenal Kit to support a healthy adrenal function and overall hormone balance.

How to Know If You Have Adrenal Fatigue vs. Hypothyroidism

Differentiating between adrenal fatigue and hypothyroidism is tricky but necessary, especially since they can go together. While lifestyle habits are essential for both, the treatments differ. Some of the symptoms mirror each other (or it's possible to have both), and they can also be attributed to other conditions, especially in the early stages.

The following information shouldn't be used to diagnose yourself, but it can be helpful to guide your conversation with your doctor or healthcare practitioner.

Signs and Symptoms of Adrenal Fatigue

  • Exhaustion 
  • Insomnia 
  • Feeling like you can't turn off or unwind (“wired but tired”)
  • Feeling stressed by everything
  • Low libido
  • Irregular menstrual cycle
  • PMS
  • Blood sugar dysregulation
  • Anxiety
  • Lightheadedness after standing up
  • Low blood pressure
  • General feelings of overwhelm about everything
  • Poor concentration
  • Difficulty recovering from exercise (or just like you can't push yourself)
  • Weight loss or weight gain

Are there blood tests for adrenal fatigue?

The short answer is no. There isn't a set test for adrenal fatigue. If I suspect HPA-axis dysregulation with a patient, I always rule out other possibilities like thyroid first (which we’ll discuss soon). You can test for adrenal function via a urinary or salivary test. But if I suspect adrenal dysregulation and other conditions have been ruled out, I will usually suggest starting with HPA-axis targeted diet, lifestyle, and supplements to get started.

If we suspect adrenal insufficiency, a morning ACTH and cortisol test should be ordered, along with 21-hydroxylase antibodies in order to understand if this is the cause of symptoms. Again, this is separate from adrenal fatigue and requires working with a provider.

Low Thyroid vs Adrenal Fatigue Symptoms

Signs and Symptoms of Low Thyroid Functioning

  • Fatigue
  • Weight gain
  • Constipation
  • Dry skin
  • Feeling cold all the time
  • Anxiety or depression
  • Weak nails
  • Low heart rate
  • High cholesterol
  • Thinning hair or eyebrows
  • Brain fog or memory issues
  • Stiff or weak muscles and joints
  • Irregular menstrual cycle
  • Infertility

Blood Tests for Low Thyroid Functioning

Unlike adrenal fatigue, there are specific blood tests for hypothyroidism, but sometimes you have to ask for a more extensive panel. Many doctors usually start with thyroid-stimulating hormone (TSH). TSH is made by your pituitary gland, and its job is to stimulate the thyroid to make more thyroid hormone. If TSH is high, it usually indicates that the thyroid isn't making enough, so it keeps pumping out more to compensate.

But a full thyroid panel is what I recommend, including:

  1. TSH
  2. Total and Free T4
  3. Total and Free T3
  4. Reverse T3
  5. Anti-TPO
  6. Anti-thyroglobulin

Testing for all of these, especially thyroid antibodies, gives a more complete picture of what's happening in your body. Sometimes you can have normal TSH, but these labs are off, indicating issues with thyroid hormone conversion.

In the case of Hashimoto's, thyroid antibodies (which measure autoimmune activity against the thyroid) are high and can start to rise long before TSH goes up.

@drjolenebrighten Don’t ignore your symptoms. #thyroid #thyroidproblems #hypothyroidism #drjolenebrighten ♬ Stuck In The Middle – Tai Verdes

Common Causes of Adrenal and Thyroid Problems

Both adrenal and thyroid can have several underlying causes. The following lists aren't exhaustive, but knowing some of the potential reasons for these conditions can empower you to dig deeper with your doctor.

What Causes Adrenal Fatigue?

The primary cause of adrenal fatigue is daily, chronic, unrelenting stress. Not everyone who deals with stress ends up with adrenal fatigue, but some people may be more predisposed. I've also seen situations where someone with a high-stress life appears to be managing just fine, and one extra thing tips them over the edge into adrenal fatigue.

Interestingly, from what I've seen in practice, hypothyroidism could predispose you to be more likely to end up with adrenal fatigue since the underlying cause is autoimmunity. Autoimmunity is inflammatory in nature and cortisol is a key hormone for managing inflammation. Inflammation is a stressor for the HPA system and can lead to symptoms of adrenal fatigue. 

Another factor is gut dysbiosis (imbalance of healthy gut bacteria) that can be linked to both adrenal fatigue and hypothyroidism. Add lifestyle habits like over-exercise, not eating enough, not sleeping, and overdoing the caffeine, and you've got yourself a recipe for burnout.

What Causes Low Thyroid Issues?

The causes of low thyroid are better understood than HPA-axis dysregulation. As I mentioned earlier, Hashimotos is the most common type of hypothyroid and is caused by an autoimmune response.

Other hypothyroid causes include:

  • Surgical removal of the thyroid (thyroidectomy)
  • Radiation exposure as a treatment for hyperthyroid (overactive thyroid)
  • Exposure to radiation in your environment (like at your job)
  • Certain medications
  • Environmental toxins
  • Infections
  • Too much or too little iodine
  • Congenital disease
  • Pituitary gland conditions

My supplement, Thyroid Support, is specifically designed to nourish and optimize your thyroid, plus give your body what it needs to use the thyroid hormone available.

Causes of Hypothyroidism

What If You Have Adrenal Fatigue as Well as Thyroid Problems?

Adrenal fatigue and Hashimotos often go hand-in-hand. The adrenals and thyroid are both part of the endocrine system responsible for making hormones. When one system is out of balance, it can have a ripple effect on the other systems.

If you think you might have adrenal fatigue and/or thyroid issues, I recommend working with a naturopathic doctor or functional medicine practitioner who can order the appropriate lab tests and help you create a healing protocol that addresses both conditions. 

A combination of supplements, lifestyle habits, and medications (when necessary) can help get both adrenal and thyroid back on track. You can grab this free meal plan and recipe guide as a starting place for optimizing your hormones.

Frequently Asked Questions (FAQs) About Adrenal Fatigue and Low Thyroid

How Do You Reverse Adrenal Fatigue?

It's absolutely possible to recover from adrenal fatigue, but it can take time and a targeted approach to your needs. A typical adrenal-supportive plan includes giving your body the nutrients to heal, learning to manage stress effectively, sleep hygiene, and avoiding things like caffeine and alcohol that can make things worse. Supplements to soothe the adrenals and help you sleep are usually included as well.

What's the Difference Between Adrenal Fatigue and Adrenal Insufficiency?

Adrenal insufficiency, or Addison's Disease, is a serious medical condition where the adrenals are damaged and unable to function. On the other hand, adrenal fatigue is not an actual medical diagnosis. It's more of a catch-all term that's often used to describe a collection of symptoms that happen when someone is chronically stressed. HPA-axis dysregulation is the condition most people are referring to when they say adrenal fatigue.

What Are Early Warning Signs of Thyroid Problems? 

Early warning signs of thyroid problems include fatigue, brain fog, weight gain, dry skin, hair loss, thinning eyebrows, feeling cold, and constipation. If you have any of these symptoms, I recommend working with a healthcare practitioner to get thyroid lab tests done.

Do Thyroid Problems Always Show Up in Blood Tests? 

No, not always. It's possible to have subclinical hypothyroidism, which means your thyroid hormone levels are normal but still have symptoms. Also, some of the more basic thyroid panels don't include all the thyroid measures, so it's possible to have an imbalance even if your levels look normal. This is why it's so important to work with a practitioner who can order the appropriate tests and also take your symptoms into account when making a diagnosis.

@drjolenebrighten What do they do? #thyroid #thyroidproblems #drjolenebrighten #hypothyroidism #health #healthy #healthylifestyle ♬ Get Low – Dillon Francis & DJ Snake

What Does Thyroid Fatigue Feel Like?

Fatigue is one of the most common symptoms of adrenal fatigue and low thyroid. Thyroid fatigue is described as feeling exhausted all the time, even after a good night's sleep. It can also include brain fog, difficulty concentrating, and feeling cold all the time.

Can Adrenal Fatigue Cause High TSH? 

If your TSH is high that points to a thyroid problem. The cause of that thyroid issue may be linked to an adrenal issue, like adrenal fatigue. It is important to look at the underlying cause of the thyroid issues and address those appropriately. 

Key Takeaways

  • Adrenal fatigue and low thyroid are both common conditions that can go hand-in-hand.
  • Adrenal fatigue can cause symptoms like fatigue, brain fog, and a feeling of being “wired but tired.”
  • Thyroid problems can also cause fatigue, brain fog, irregular periods, and weight gain.
  • If you think you might have adrenal fatigue or low thyroid, I recommend working with a practitioner to get a proper diagnosis and create a healing protocol for you.

Balanced hormones are essential for optimal wellness. If you aren't sure where to start, I've created a free Hormone Balancing Starter Kit to guide you on your journey.

Get Your FREE Hormone Starter Kit with

7 Day Meal Plan & Recipe Guide

This starter pack is exactly what every woman needs to bring her hormones back into balance!

Hormone Starter



  1. American Thyroid Association. General Information/Press Room. 2022.
  2. Sheng JA, Bales NJ, Myers SA, Bautista AI, Roueinfar M, Hale TM and Handa RJ. The Hypothalamic-Pituitary-Adrenal Axis: Development, Programming Actions of Hormones, and Maternal-Fetal Interactions.. Front. Behav. Neurosci.. 2021. 14. 601939.
  3. Chaker L, Bianco AC, Jonklaas J, Peeters RP.. Hypothyroidism.. Lancet. 2017. 390(10101). 1550-1562.
  4. American Thyroid Association. Thyroid Function Tests.
  5. Pearce EN, Braverman LE. Environmental pollutants and the thyroid. Best Pract Res Clin Endocrinol Metab. 2009. 23(6). 801-813.
  6. Endocrine Society. Adrenal Insufficiency | Endocrine Society.. Endocrine.org. 2022.
About The Author

Dr. Jolene Brighten

Facebook Twitter

Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.