Is Your Thyroid the Reason You Feel So Exhausted? A Naturopath Explains
By Kylie Sartori | Kylie Sartori Naturopathy, Spotswood Melbourne
You are tired in a way that sleep does not fix.
You feel cold when everyone else is comfortable. Your weight has shifted despite nothing obvious changing in your diet. Your brain feels foggy, your mood is flat, your hair is coming out in the shower, and your digestion has slowed down in a way that feels new and uncomfortable.
Individually, any one of these things might be explainable. Together, they paint a very specific picture.
The thyroid is one of the first places I look when a client presents with this cluster of symptoms. It is a small gland with an enormous reach, and when it is not functioning well, the effects ripple through almost every system in the body.
What the Thyroid Actually Does
Your thyroid is a small butterfly-shaped gland sitting at the front of your neck.
Its primary job is to produce two hormones, T3 and T4, that regulate your body's metabolism. And metabolism here does not just mean weight. It means the rate at which every cell in your body produces and uses energy. Your heart rate, your body temperature, your digestive speed, your cognitive function, your mood, your menstrual cycle, and your ability to maintain a healthy weight are all directly governed by thyroid hormone activity.
The thyroid also produces calcitonin, a hormone that regulates calcium and phosphate levels and supports bone density.
When thyroid output is optimal, all of those systems run smoothly and in good coordination. When it is not, the dysregulation tends to be felt everywhere at once, which is what makes thyroid dysfunction so significant and so frequently missed when individual symptoms are investigated in isolation.
The Two Main Types of Thyroid Dysfunction
Hypothyroidism: underactive thyroid
Hypothyroidism is the most common thyroid condition and occurs when the thyroid is not producing enough T3 and T4 to meet the body's needs.
The most common cause in Australia is Hashimoto's thyroiditis, an autoimmune condition where the immune system produces antibodies that attack the thyroid gland over time. Because Hashimoto's develops gradually, it can be present for years before TSH levels shift enough to show on standard blood testing, yet symptoms are already significantly impacting quality of life.
Hypothyroidism can also result from poor nutrition, particularly deficiencies in iodine and selenium, chronic stress, certain medications, and as a consequence of treating hyperthyroidism.
Symptoms of an underactive thyroid include fatigue and exhaustion that does not improve with rest, unexplained weight gain, feeling cold all the time, hair loss and thinning, brain fog and memory difficulties, constipation, slow digestion, low mood, irregular or absent periods, and puffy face and hands.
Hyperthyroidism: overactive thyroid
Hyperthyroidism occurs when the thyroid produces too much thyroid hormone, accelerating the body's metabolic rate beyond what is healthy.
The most common cause is Grave's disease, another autoimmune condition. Thyroid inflammation and, in rare cases, nodules or thyroid cancer can also drive excess thyroid hormone production.
Symptoms of an overactive thyroid include anxiety and irritability, rapid or irregular heart rate, unexplained weight loss despite normal or increased appetite, excess sweating, feeling hot all the time, difficulty sleeping, trembling hands, and in Grave's disease specifically, changes to the eyes including puffiness and protrusion.
Why Thyroid Function Gets Disrupted
The thyroid is more sensitive to its environment than most people realise.
Stress is one of the most significant drivers of thyroid dysfunction. Cortisol, the primary stress hormone, directly inhibits the conversion of inactive T4 into active T3, which is the form of thyroid hormone the body's cells can actually use. Chronic stress also depletes the nutrients the thyroid depends on and disrupts the hormonal signalling network that thyroid function sits within. A client can have adequate T4 production and still feel hypothyroid if conversion to T3 is being impaired by ongoing stress.
Gut health is directly connected to thyroid function in ways that are still underappreciated clinically. Approximately 20 percent of T4 to T3 conversion happens in the gut, facilitated by healthy gut bacteria. When the microbiome is disrupted, that conversion is impaired. Poor gut health also leads to inadequate absorption of the nutrients the thyroid depends on, particularly selenium, iodine, zinc, and iron. Intestinal permeability is also associated with increased autoimmune activity, which is relevant for Hashimoto's and Grave's disease. Addressing gut health is often a foundational part of thyroid treatment in naturopathic practice.
Nutrient deficiencies are both a cause and a consequence of thyroid dysfunction. Iodine is essential for the production of T3 and T4. Selenium is required for the conversion of T4 to active T3 and protects the thyroid gland from oxidative damage. Zinc supports thyroid hormone production and receptor sensitivity. Iron deficiency impairs the enzyme responsible for thyroid hormone synthesis. Vitamin D deficiency is strongly associated with autoimmune thyroid conditions.
Gluten and autoimmunity are worth understanding for anyone with Hashimoto's. The molecular structure of gliadin, the protein component of gluten, closely resembles thyroid tissue. In people with Hashimoto's, consuming gluten can trigger an immune response that cross-reacts with thyroid tissue, driving antibody levels and accelerating glandular damage. Reducing gluten is one of the most consistently useful dietary interventions in Hashimoto's management.
Goitrogens are compounds found in certain everyday foods that can interfere with thyroid hormone production when consumed in very large amounts. They are found in raw brassica vegetables including broccoli, cauliflower, kale, cabbage, and brussels sprouts, as well as in unfermented soy products. It is worth noting that cooking significantly reduces goitrogenic activity, and moderate consumption of these foods, particularly cooked, does not pose a meaningful risk for most people. They are genuinely nutritious and anti-inflammatory foods that should not be avoided wholesale.
Inflammation is both a driver and a result of thyroid dysfunction. Any source of systemic inflammation, whether from gut permeability, food intolerances, chronic infection, or autoimmune activity, places additional stress on a vulnerable thyroid and can accelerate the progression of autoimmune thyroid conditions.
Medications including lithium, amiodarone, and certain immunosuppressants can directly impair thyroid function. If you are on any long-term medication and experiencing thyroid symptoms, it is worth discussing with both your GP and a naturopath whether your medication could be a contributing factor.
The Problem With Standard Thyroid Testing
This is worth addressing directly because it is one of the most common frustrations I hear in clinic.
Standard thyroid testing through a GP typically measures TSH, thyroid stimulating hormone, alone. TSH is a pituitary hormone, not a thyroid hormone. It tells us how hard the pituitary is working to stimulate the thyroid, which is useful, but it does not tell us how much T3 and T4 are actually in circulation, how well T4 is converting to active T3, or whether thyroid antibodies are present.
Many people with significant thyroid symptoms are told their thyroid is normal because their TSH falls within the reference range. What most people do not realise is that the reference range for TSH is broad, and optimal function sits within a narrower band than the range suggests. Someone with a TSH at the top of the normal range and Hashimoto's antibodies present may be experiencing significant symptoms while being told everything is fine.
A comprehensive thyroid panel includes TSH, free T3, free T4, reverse T3, and thyroid antibodies including anti-TPO and anti-thyroglobulin. This gives a complete picture of what is actually happening rather than a single marker that can miss a great deal.
If your symptoms are telling you something is wrong and your standard thyroid test is coming back normal, a more comprehensive assessment is worth pursuing. You can read more about the functional testing I use in clinic to get a fuller picture.
Supporting Thyroid Health Naturally
A naturopathic approach to thyroid health focuses on removing the barriers to optimal thyroid function and providing the nutritional and herbal support the thyroid and immune system need to function well.
Dietary support centres on ensuring adequate intake of thyroid-essential nutrients, reducing gluten and inflammatory foods where autoimmunity is present, supporting gut health and T4 to T3 conversion, and managing blood sugar stability, which affects thyroid hormone receptor sensitivity.
Targeted nutritional support includes selenium, which is one of the most important nutrients for thyroid health and is frequently deficient, iodine at appropriate therapeutic doses, zinc, iron where deficiency is present, vitamin D, and magnesium.
Herbal medicine has a meaningful role particularly in stress support and inflammation management. Adaptogenic herbs support the HPA axis and reduce the cortisol burden on T4 to T3 conversion. Anti-inflammatory herbs support the immune dysregulation that drives autoimmune thyroid conditions.
Lifestyle support, particularly around stress management, sleep quality, and reducing inflammatory exposures, forms the foundation that everything else builds on.
The specific protocol depends entirely on the individual picture, which is why testing and a thorough clinical assessment are the most useful starting point.
Working Together
If the symptoms in this post have resonated, or if you have been told your thyroid is normal but you still do not feel well, it is worth getting a more complete picture. I see clients in person at my Spotswood clinic in Melbourne and via telehealth across Australia. A naturopathic thyroid consultation looks at your full hormonal, nutritional, and gut health picture alongside comprehensive thyroid testing to understand what is actually driving your symptoms.
You can also explore what conditions I work with or find out more about functional testing and what a comprehensive thyroid assessment looks like in practice.
Frequently Asked Questions About Thyroid Health
Can I have thyroid symptoms even if my TSH is normal? Yes, and this is one of the most common clinical scenarios I see. TSH alone does not tell the full story of thyroid function. If your free T3, free T4, reverse T3, or thyroid antibodies are not also assessed, significant thyroid dysfunction can be missed entirely. If your symptoms are consistent with thyroid imbalance and standard testing has come back normal, a comprehensive thyroid panel is the logical next step.
What is the difference between Hashimoto's and hypothyroidism? Hashimoto's is an autoimmune condition where the immune system attacks the thyroid gland, gradually impairing its ability to produce adequate thyroid hormone. Hypothyroidism is the clinical outcome of insufficient thyroid hormone, regardless of the cause. Hashimoto's is the most common cause of hypothyroidism, but not the only one. The distinction matters because treating Hashimoto's involves addressing the autoimmune component, not just supporting thyroid hormone output.
Does gut health really affect the thyroid? More than most people realise. Approximately 20 percent of T4 to T3 conversion happens in the gut with the help of specific bacterial enzymes. Poor microbiome health impairs this conversion, reducing the amount of active thyroid hormone available to cells even when the thyroid is producing adequate T4. Gut permeability is also associated with increased autoimmune activity, which is directly relevant for Hashimoto's and Grave's disease.
Should I avoid broccoli and kale if I have a thyroid condition? Not necessarily. Goitrogens in raw brassica vegetables can interfere with thyroid hormone production when consumed in very large amounts, but cooking significantly reduces their goitrogenic activity. For most people with thyroid conditions, moderate consumption of cooked brassicas is not a concern and the nutritional and anti-inflammatory benefits of these vegetables outweigh the theoretical goitrogenic risk. Very high intake of raw brassicas or unfermented soy is worth discussing with your practitioner if you have a thyroid condition.
Can stress cause thyroid problems? Yes. Chronic stress elevates cortisol, which directly impairs the conversion of T4 to active T3 and disrupts the hormonal signalling network that thyroid function depends on. Stress also depletes the nutrients the thyroid requires, including selenium, zinc, and B vitamins, and drives the systemic inflammation that can trigger or accelerate autoimmune thyroid conditions. Managing the stress response is not peripheral to thyroid treatment. It is central to it.
Kylie Sartori is a degree-qualified naturopath based in Spotswood, Melbourne, specialising in thyroid health, hormonal health, gut health, and autoimmune conditions. She offers in-person consultations at her Spotswood clinic and telehealth appointments for clients across Australia.
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