The Brain, Thyroid, Adrenal Connections

by | Adrenals, Brain, Functional Medicine, Optimal Health, Thyroid | 0 comments

The Brain Thyroid Adrenal Connection S1 Ep4

You can listen to this episode of The Goode Health Podcast by clicking here.

Or you can read the (timestamped) transcript below.

Please note: Transcript is automatically generated.

[00:00:00] Hi, and welcome to the Goode Health Podcast. I’m your host, Nicole Goode, a registered nutritional therapy practitioner and functional medicine practitioner. Join me as we explore thyroid, brain and fatigue conditions with positivity. From Hashimoto’s to multiple sclerosis, chronic fatigue to adrenal dysfunction.

I’ve got you covered with expert advice and tips to help you take action now and inspiring real patient stories from successful individuals who refuse to let their health hold them back. Start your journey to Goode Health today. And don’t forget, come and join the conversation on Instagram @Goode_Health.That’s GOODE, or visit my website at to find out more. 

Welcome to today’s episode of the Goode Health Podcast. So I often get asked about why I subspecialised into thyroid, brain and adrenals. So I am an autoimmune specialist and I work with people with all sorts of different autoimmune disorders.

I also studied neuroscience at university and have a neurological autoimmune condition myself. So specialising into the brain was a little bit of a no-brainer. The more I practiced in functional medicine, the more I found links to other areas cropping up time and time again, and working on the brain, I see people with neurological conditions, but also people with symptoms such as fatigue and brain fog, and this commonly involves the adrenals and the thyroid.

Many with thyroid conditions have brain dysfunction. Many with fatigue have thyroid or adrenal dysfunctions. Many with adrenal issues have brain imbalances. People with dysautonomia, for example, have their nervous system, the brain, and commonly the adrenals impacted, with symptoms including fatigue. The three are inextricably linked, and they’ve become a real focus for me in clinic.

And functional medicine works on the premise that the body is all interlinked. So you can’t just look at one area. This is the difference [00:02:00] between functional medicine and conventional medicine. So in conventional medicine, you know, you go and see a specialist who works in a particular area of the body.

So you go and see, you know, an endocrinologist, or a rheumatologist or a neurologist. The point with function of medicine is that we are looking at the body as a whole. So you need to look at each person as an individual, because we’re all different. We’ll all react to things differently. We’ll all respond to things differently, and we will all have different root causes and underlying imbalances.

But you also need to look at the body as a whole, as one interconnected web. So in today’s episode, what I really want to jump into is some of these interconnections between the thyroid, the brain, and the adrenals. And why I feel it’s so important that we look at all of them together. 

So the brain thyroid and the adrenal glands, they are hugely interconnected by this complex web of communication and influence within the body, and this connection plays a really vital role in regulating various physiological processes and maintaining your overall health. 

So the thyroid and the adrenal glands, they’re both part of the endocrine system and they work together to maintain the body’s overall hormonal balance and your response to stress. And there’s two particular axes that go through the body that we, we need to consider and that I work on in clinic all the time.

The first one of these is the hypothalmic pituitary thyroid axis. So the HPT axis, the hypothalamus is in the brain. The pituitary gland is in the brain, and then we have the thyroid. And these make up this HPT axis and this axis regulates the production and the release of thyroid hormones. The hypothalamus will release thyrotropin releasing hormone TRH, which stimulates the pituitary gland also in the brain to release thyroid stimulating hormones.

So TSH. [00:04:00] And TSH then acts on the thyroid gland promoting the synthesis and secretion of the thyroid hormones, T3 and T4. So proper functioning of the HPT axis is essential for maintaining thyroid hormone balance. Two parts of the axis are actually in the brain. 

Then we have the hypothalmic pituitary adrenal axis. So this is the HPA axis. This is one that’s probably a bit more commonly talked about, and you may have heard of. The HPA axis regulates the body’s response to stress, so it involves interactions between the hypothalamus in the brain, the pituitary in the brain, and the adrenal glands. And when the brain perceives stress, the hypothalamus will release corticotropin releasing hormones, CRH, and that stimulates the pituitary gland to release adrenalcorticotrophic hormones, so ACTH and the ACTH in turn signals the adrenal glands to produce and release cortisol and your other stress hormones. And both the thyroid and the adrenal glands can be influenced by this HPA axis and its response to stress. So again, we’ve got an adrenal axis, but two parts of that are in the brain, the hypothalamus and the pituitary.

We then need to look at cortisol and thyroid function. So cortisol is a hormone that is produced by the adrenal glands, and it can have an effect on thyroid function. So if you’ve got elevated levels of cortisol, which we see regularly with chronic stress or adrenal dysfunction, it can lead to decreased levels of TSH, or it can lead to altered conversion of T4 to the active T3 form that we need.

And this can result in reduced thyroid hormone production and function. So even though we’re talking about cortisol, which is a hormone secreted by the adrenal glands. Actually, we’re getting a lot of thyroid function issues coming from that. We then also have this process of feedback regulation, so there’s this feedback [00:06:00] relationship between the adrenal and the thyroid glands.

So thyroid hormones, specifically T3, can influence the sensitivity and how the adrenal glands will respond to ACTH and cortisol. So if we don’t have enough thyroid hormone levels, which we see in people with hypothyroidism or Hashimoto’s, that can lead to reduced adrenal responsiveness and altered cortisol production.

So commonly people with thyroid conditions also have adrenal issues. And of course, the adrenal and the thyroid, we get very shared symptoms so they can manifest with similar symptoms such as fatigue, weight changes, mood disturbances, disrupted sleep patterns, and it’s not uncommon for individuals who have a thyroid disorder to also have an adrenal disorder and vice versa. So addressing both thyroid and adrenal health is absolutely necessary if we are going to look at optimal hormonal balance and optimal overall wellbeing. So let’s dig a little bit deeper into the brain’s role in all of this, because we’ve seen it’s very interlinked with these, with these two axes. So the hypothalamus and the pituitary particularly, are involved in the HPT and HPA axis, and these areas communicate with the thyroid, they communicate with the adrenal glands all through a series of hormonal signals. So let’s dig into the brain. 

So the hypothalamus, it is a, a very small part of the brain, but also a very crucial part of the brain, and it’s located below the thalamus. It’s at the base of the brain and it plays a very vital role in maintaining homeostasis. So regulating various physiological processes in the body, and it also links the nervous system to the endocrine system. So the endocrine system, hormones, this is your thyroid and adrenals, both part of the endocrine system.

So let’s look at some of the key functions of the hypothalamus. We’re talking about things like regulation of body temperature, so the hypothalamus can help to regulate body temperature by monitoring internal and external temperature changes, it will then [00:08:00] initiate the appropriate response and will help maintain a stable core body temperature.

Now, we know people who have adrenal issues and thyroid issues often have problem with this regulation of body temperature. It also controls hunger. So the hypothalamus contain specialised regions that monitor the nutrient and the energy levels in the body. It regulates appetite, feeding behaviours, and responds to all these hormonal signals and coordinates the release of the hunger hormones.

So again, nutrients, energy. This is all symptoms and things that we see in thyroid and adrenal cases. We then have to look at the sleep wake cycle regulations. So the hypothalamus plays a role in regulating our circadian rhythm. It receives input from the eyes regarding light exposure and helps to synchronise the body’s internal clock.

So it’s influencing those sleep patterns and the release of those sleep related hormones. And then we have to look at the autonomic nervous system regulation. So the hypothalamus helps to control the autonomic nervous system, and this regulates any of the involuntary functions within the body, so anything such as heart rate, blood pressure, digestion, your respiratory rate, anything that you don’t need to think about, anything that happens automatically in the body is regulated by this autonomic nervous system.

Which is partially controlled by the hypothalamus, also controls both the sympathetic and the parasympathetic branches of the autonomic nervous system helping to maintain that balance. We know that movement between the sympathetic and parasympathetic branches of the autonomic nervous system are what moves us between the rest and digest state and the fight and flight state. So again, we’re involving the adrenals in this. 

The hypothalamus is also produces and releases several hormones that control the release of hormones from the pituitary gland, so these hypothalamic releasing hormones. And also the hypothalamic inhibiting hormones help to regulate various hormones that are involved in growth, reproduction, stress, [00:10:00] water balance, all of these things, all things again, which are impacted by thyroid and adrenals.

The hypothalamus also helps with emotional and behavioural regulation, so it plays a role in the expression and regulation of emotions and is therefore involved in the stress response. And it can also be involved in the water and electrolyte balance. So we know that people, some people with thyroid maybe have issues with electrolyte balance, but also it regulates our thirst and the release of the antidiuretic hormone, ADH, to maintain proper fluid balance.

So all of these functions highlight how critical a role the hypothalamus has in maintaining complete balance on homeostasis within our body, and it helps to coordinate various physiological processes in the body. It works in very close connection to other areas of the brain and very close connection with the endocrine system.

All of this is done through hormones, and this all helps to ensure the body’s overall wellbeing and proper functioning. And of course, it’s specifically linked to the thyroid and the adrenals. So the hypothalamus releases thyrotropin releasing hormone TRH. This stimulates the pituitary gland to produce thyroid stimulating hormone, TSH and adrenocorticotropic hormone, ACTH.

The TSH in turn acts on the thyroid gland to release the thyroid hormones, T3 and T4, while ACTH stimulates the adrenal glands to produce the cortisol and other stress related hormones. So you can see TSH, which for those of you who have got a thyroid issue listening to this, you know, you’ll prob, you’ll be very familiar with TSH.

It’s the marker that is regularly measured by the NHS to check your thyroid function. It’s not actually a thyroid hormone, it’s a brain hormone. So you can see how interlinked the thyroid and the brain are. You know, as for adrenals, we’re digging into that hypothalamic pituitary adrenal access to the HPA [00:12:00] axis.

When the brain perceives stress, the hypothalamus will release corticotropin releasing hormones, the CRH, and signal that pituitary gland to release the adrenocorticotropin hormone, ACTH, which in turn is gonna stimulate those adrenal glands to produce cortisol. So it’s playing the really crucial role in your body’s stress response and maintaining balance.

All of that is linked between the hypothalamus in the brain and the thyroid and the adrenals, but then also in there we’ve got this pituitary gland. So let’s have a look at the pituitary gland. It’s often referred to as the master gland. It’s actually a small pea-sized gland that’s located at the base of the brain just below the hypothalamus.

And it consists of two parts, the anterior pituitary and the posterior pituitary. And each part’s got different functions and connections to other glands in the body. So let’s have a look at some of the key functions of the pituitary gland, and its links with thyroid and adrenal glands. 

So we have to consider hormones secretion. So the pituitary gland secretes various hormones that regulate and control the activity of other endocrine glands in the body of which we know the thyroid and adrenal are. So the anterior pituitary produces and releases several hormones, including growth hormone prolactin, adrenal corticotropic hormone, thyroid stimulating hormone follicle stimulating hormone, and so many more. So we’ve got sex hormones in there, thyroid hormones in there, adrenal hormones. 

And the posterior pituitary stores and releases two hormones that are produced by the hypothalamus, so oxytocin and the antidiuretic hormone. So it’s very heavily linked in with your hormone secretion. 

Then the pituitary is also specifically linked to the thyroid gland. They’ve got an extremely close relationship. So through. TSH the hypothalamus will release TRH, which will stimulate the anterior pituitary to release TSH. All of that is happening in the brain, so even though we are talking thyroid here, It’s all currently going on in the brain. The TSH [00:14:00] will then act on the thyroid gland.

So now we’re bringing the thyroid gland into this, and this will promote the production and release of the thyroid hormones, T3, T4, and it will also help regulate the feedback loop between thyroid function and maintaining proper levels of thyroid hormones in the body. 

And then we have to look at the pituitary with the adrenal function. So the pituitary gland also influences your adrenal glands through the production of the ACTH. So the outlayer of the adrenal glands is called the adrenal cortex. That’s what produces the cortisol, which is the stress hormone that you’ve probably all heard of. Cortisol plays a role in regulating your body’s response to stress, so it helps maintaining blood sugar, it helps modulate immune responses.

It’s got so many roles within the body and in response to signals from the hypothalamus, the pituitary will secrete this ACTH and stimulate the adrenal gland to release the cortisol and other steroid hormones. And again, we have this feedback loop. So the pituitary gland receives feedback from target organs and glands to regulate hormone secretion.

So, for example, the levels of thyroid, hormones and cortisol in the bloodstream can influence the production and release of TSH and ACTH. It’s almost like your body will be reporting back to say that it needs more, or that it can stop releasing a hormone so your body reports back to the brain, to the pituitary within the brain on this feedback loop, and this system helps to maintain hormonal balance.

So it’s really important to note that the connections and the interconnections between the pituitary, the thyroid, the adrenal, they’re really complex. They involve multiple feedback loops, lots of regulatory mechanisms, but dysfunctions or imbalances in these systems can lead to disorders such as hyperthyroidism, Hashimoto’s, hyperthyroidism, adrenal insufficiency, Cushing syndrome, as well as things like adrenal dysfunction and burnout.

So you can see how heavily linked the [00:16:00] hypothalamus and the pituitary are to the thyroid and the adrenals. But what about other areas of the brain? Because it’s not just the hypothalamus and the pituitary that are involved here. So the thyroid is also really interconnected with the cerebellum in the brain, and this is because cerebellum degeneration is actually really common in people who have Hashimoto’s.

So Hashimoto’s thyroiditis is an autoimmune hypothyroid disorder. And it’s characterised by inflammation of the thyroid gland, which leads to this hypothyroidism. So this underactive thyroid, and there’s been a really distinct link discovered between Hashimoto’s and cerebellum degeneration. Now, cerebellum degeneration refers to the loss of function and structure in the cerebellum, which is a part of the brain that is responsible for coordinating voluntary movements.

It’s also responsible for your balance, for your posture for motor learning. So all really important things. And in the context of Hashimoto’s cerebellum degeneration is thought to be an autoimmune mediated process. So this is where the immune system will mistakenly attack and damage the cerebellum. And this is another reason why it’s really important to properly manage and balance your thyroid, but also if you have Hashimoto’s that or, or graves that underlying autoimmune processes that are also going on in the body.

So the exact mechanism that links this Hashimoto’s and cerebellum degeneration is not really yet fully understood. However, we believe it’s linked to autoantibodies. Specifically we’re looking at anti TG6 Thyroglobulin and anti GAD, which is glutamic acid decarboxylase, and it’s thought that these antibodies may play a role in targeting the cerebellum.

So these are antibodies which are also found in other autoimmune conditions, and they can cause inflammation and damage to the cells and tissues, and that’s what’s happening with the cerebellum. So symptoms that we often see in the [00:18:00] cerebellum degeneration, which is associated with this Hashimoto, this hypothyroid can vary from person to person, but we might see things like, Ataxia.

So this is common of cerebellum degeneration, and it refers to a lack of coordination, lack of balance. You might just see somebody as being a bit clumsy. They might be a little bit unsteady. People can have difficulty with maybe really fine motor skills, so maybe things like writing or doing up little fiddly buttons on things.

They may also experience problems with walking. They may have, their gait may be a little bit unstable, or they may have coordination problems. And then we can also see things like tremors. So some people can develop these involuntary movements. Typically it affects the hands and other extremities.

We can also see things like difficulties with speech. You might have unclear speech or you might have slurred speech. And then we can see something called nystagmus, which is abnormal eye movements, so categorised by like kind of rapid and involuntary movements and it can cause vision problems. And then we also see these cognitive and emotional changes.

So in some cases, cerebellum degeneration can lead to difficulties with memory, with attention. So, with some executive functions and individuals may experience emotional changes such as depression and anxiety and mood swings. So while it’s important to note that not all people with Hashimoto’s will develop cerebellum degeneration, if you know thyroid disorders, if you know Hashimoto’s, if you know about these things, you can probably recognise some of these symptoms.

You very, very commonly, people will have maybe anxiety or depression with it. They may have, you know, lots of brain fog, maybe unsteady, maybe have clumsy movements. These are all really common things that we see a lot, struggle with memory. So you may recognise some of those symptoms as being thyroid symptoms, but actually they could really be this kind of brain symptom coming from this cerebellar degeneration.[00:20:00] 

So that’s the thyroid and other areas of the brain that the thyroid links to. But what about the adrenals? Because the adrenals are also linked to other areas of the brain and also have an impact on brain function. So cortisol can actually have an effect on the brain and the central nervous system. So it can influence mood. It can influence memory, it can influence cognition. And it can actually also influence the regulation of emotions, so elevated or chronic cortisol, which we get as a result of chronic stress or adrenal dysfunction. It can contribute to things like mood disorders, cognitive impairment, changes in behaviour, and then we have to look at the adrenal medulla and catecholamines because the inner layer of the adrenal glands, which is known as the adrenal medulla, it produces these catecholamines.

And these include things like adrenaline and noradrenaline. These hormones are involved in the body’s fight or flight response, which prepares the body for action when there’s this, you know, a perceived threat. And catecholamines can also have an effect on brain function because they cause this increased alertness, this heightened sensory perception, increased heart rate, increased blood pressure.So all the things to get you ready for your fight and flight response to get you out of danger. And that is having an impact on the brain. 

So that’s kind of all the interconnections between, or some of the interconnections between the brain, the adrenals, and the thyroid. If you’ve got adrenal dysfunction or if you’ve got thyroid dysfunction.

But what about if you’ve been diagnosed with a neurological condition? So instead of a thyroid one or adrenal one, you know, maybe you’ve been diagnosed with something neurological and people commonly sort of think that actually this way round, it’s more unlikely. So they can kind of maybe see the links between thyroid and adrenal. They can see that, you know, if you had a thyroid condition, maybe it would impact your adrenals and likewise the other way round. But people generally don’t see the interconnections between having a neurological disease and the impact of that on your thyroid and adrenals. So let’s take a [00:22:00] look at a few examples.

So disruption of the HPA axis. We know that in neurological conditions that affect the hypothalamus and pituitary gland, it can disrupt the normal regulation of HPA axis. That’s the same HPA axis that plays that crucial role in coordinating the body’s stress response and cortisol production.

So if the neurological condition causes dysfunction in the hypothalamus or pituitary, it can lead to abnormal cortisol levels and adrenal dysfunction. So you could be diagnosed with a neurological disorder, but actually have dysfunction of the adrenals as well. We then get neurological conditions that affect the hypothalamus, or the pituitary gland that can disrupt the normal regulation of the thyroid hormones.

So these areas of the brain that impact and are involved in the adrenals and the thyroid can also be impacted by various neurological conditions. We then want to look at the autonomic nervous system dysregulation. So neurological conditions that involve the autonomic nervous system. They can impact adrenal function, so the autonomic nervous system controls those involuntary functions.

Including the regulation of the adrenal glands. So conditions like autonomic neuropathy or dysautonomia, they can disrupt the normal signalling between the brain and the adrenals and they can lead to these abnormalities in adrenal hormone production and release. So again, you can be diagnosed with a neurological conditions, something like a dysautonomia and there’s various different autonomic disorders, you know, things like pots, orthostatic intolerance. And these can lead to an imbalance in the adrenals. So you might get diagnosed with dysautonomia, but you may actually need to also work on your adrenal glands. 

Then we have to look at things like brain lesions. So certain neurological conditions such as multiples sclerosis, for example, these can directly affect the hypothalamus or the pituitary gland, which are involved in [00:24:00] regulating this adrenal function and the thyroid function if the lesion are formed in these areas, and these abnormalities can disrupt normal communication between the brain and the adrenals and the brain and the thyroid. So we can see adrenal dysfunction, we can see thyroid dysfunction. So it really depends on where those lesions are in the brain with a condition like multiple sclerosis as to what else will be impacted within the body.

And then we need to look at autoimmune mechanisms. So some neurological conditions have an autoimmune component, and this is where the immune system is mistakenly attacking its body’s own tissue. So again, at multiple sclerosis, And we also know that we have autoimmune thyroid conditions, so Hashimoto’s thyroiditis, Graves disease, and these can be associated with certain neurological conditions.

So we know things like multiple sclerosis and myasthenia gravis are actually quite relatively heavily associated with the autoimmune thyroid disorders. So the Hashimoto’s and the Graves, and we know that once you’ve got one autoimmune disease, you are likely to get more. So it’s important to know these links between these neurological autoimmune conditions and the thyroid autoimmune conditions, and the autoimmune process that impacts the thyroid gland and leads to these hyperthyroidism and the hyperthyroidisms.

We then also need to look at like medication side effects. So some medications that are used to manage neurological conditions, it actually might not be the neurological condition itself that will impact adrenal function, but actually the medication that you have to take for the neurological condition, that can have a, one of the side effects that can be impact on the adrenal function.

So for example, long-term use of things like corticosteroids, which are used to manage inflammation. In certain inflammatory neurological conditions such as multiple sclerosis or certain types of epilepsy, these can suppress the adrenal gland’s ability to produce cortisol, and that can lead to adrenal insufficiency. Other medications can impact thyroid function. 

And then [00:26:00] we have the stress and psychological factors. So, you know, neurological conditions in themselves are associated with increased stress and psychological burden. So it’s known that when people have heart or brain related conditions, that actually anxiety, not necessarily from the condition, but just around having those conditions is quite likely.

And that’s because subconsciously we know that actually, you know, we need our heart and brain. They’re pretty vital organs. We know we need them, so, there is a known increased stress factor when we have conditions that are like, are neurological. And this chronic stress impacts the HPA axis. It impacts the HPT axis as we’ve already discussed, and therefore adrenal and thyroid function.

And if we’ve got any of that prolonged activation to stress response, which if you’re diagnosed with a neurological condition, you likely will have, it can lead to this dysregulation of the cortisol production. Which can lead to this adrenal dysfunction and it can lead to this disruption of thyroid hormones.

And then we have to consider finally the impact of metabolism and energy balance. So in these neurological conditions that affect the central nervous system, that can have indirect effects on your metabolism and energy balance, and that can influence your thyroid function. And we know that energy and fatigue is a big symptom of the thyroid conditions.

So when we take a functional medicine approach to our bodies. You can see how I couldn’t possibly work on the brain without working on the thyroid and the adrenals as well. Likewise. I couldn’t work on the thyroid without looking at the brain and the adrenals, or the adrenals without looking at the thyroid and the brain.

The three are so inextricably linked, and it’s really important that we take that full body approach. Now, none of the information here should be taken as medical advice, and you should always seek help from professional if you’re [00:28:00] concerned about any symptoms. However, addressing the connection between the brain, the thyroid, and the adrenals often actually requires a holistic approach.

We can do things like promoting stress management techniques. We can optimise nutrition, ensure that you’re getting adequate sleep. We can address underlying imbalances through really targeted interventions. As well as looking at the actual diagnoses that you have, so looking at if you have a thyroid disorder, an adrenal dysfunction, or a neurological condition.

And through the use of functional medicine and nutritional medicine and lifestyle modifications, it’s possible to support your health and wellbeing of all of these interconnected systems. And it’s really important that we understand and we nurture this connection. It’s really crucial for achieving optimal brain function, thyroid health, and adrenal balance.

So if you do have one of these conditions, if you have a thyroid dysfunction, an adrenal dysfunction, or a neurological condition, it’s really important that you are asking yourself. Have you actually looked at the other parts of these interconnections? If you’ve been diagnosed with a neurological disease, have you actually considered the impact on your thyroid and your adrenals?

If you’ve got a thyroid condition, have you looked at the adrenals and the brain? It’s really important that we take a holistic approach, and that is how we see the really positive impact and benefits in your health when we’re working with these conditions. So as ever, if you are looking for any support you’ve got any questions, please do feel free to reach out.

My details will be below in the show notes. You can always follow me on Instagram and send me a DM. My DM doors are always open. And I look forward to speaking to you next time. 

I hope you enjoyed this episode of The Goode Health Podcast. Do share the episode with anyone who you think it may benefit or who may enjoy it, and help me spread the word by rating the episode or leaving a review.

If you want more, you can find other episodes in the series on your podcast app or sign up to my free [00:30:00] newsletter. Not only will you get information on new episodes launching, but we cover lots of health topics with the Ask Nicole section where you can send in your questions. My favourite recipes, my favourite products, Tips and tricks to help you on the road to Goode Health and much more.

You can sign up free of charge at Also linked below. I hope you have a lovely week. Don’t forget to hit subscribe and I’ll see you next time.




You may Also Like..


Submit a Comment

Your email address will not be published. Required fields are marked *

Hey there, I'm Nicole

Founder & Clinical Director of Goode Health – Winner of Functional Medicine Clinic UK 2023 at the Health, Wellness & Beauty Awards. Read my articles here we discuss health & wellness topics as well as myth busting and tips & tricks. And don’t forget to join the conversation on instagram @goode_health.