You eat relatively well, try to stay active, and yet you keep getting sick—again and again. Another cold, another sore throat, another round of antibiotics. If this sounds familiar, it might be time to take a deeper look at your immune system.
At ADHD Naturopathic Clinic, we often work with clients who feel like their immune system is “just not what it used to be.” The truth is, many factors can wear down your body’s natural defences—and it’s not always obvious. Today, we’ll explore why your immune system might be running on empty, and how herbal medicine and functional testing can help you rebuild your strength from the ground up.
What Causes an Exhausted Immune System?
Your immune system doesn’t just stop working one day. It gets slowly worn down—by poor sleep, long-term stress, gut issues, nutrient deficiencies, and chronic inflammation. Here’s a closer look at the key players:
Chronic Stress: The Silent Immune Suppressor
In today’s fast-paced world, stress has become a constant background noise in our lives. Whether it's work deadlines, financial pressures, parenting challenges, or even just doom-scrolling on your phone late at night, your body perceives all of it as a threat. And when your body senses danger, it activates the fight-or-flight response—a brilliant survival mechanism for short-term emergencies, but a serious problem when it’s triggered constantly.
Some of the signs your immune system may be stress-compromised:
- Frequent colds or infections
- Slow recovery from illness
- Cold sores or shingles flaring up
- Autoimmune flares
- Feeling “run down” but unable to rest
At the centre of this stress response is the HPA axis (Hypothalamic-Pituitary-Adrenal axis), which signals the adrenal glands to release cortisol, your main stress hormone. In small bursts, cortisol is helpful—it gives you energy, sharpens your focus, and temporarily boosts immune response. But when stress is chronic, this system becomes dysregulated. Cortisol levels stay elevated, and over time, this has a profound impact on your immune system.
Prolonged cortisol exposure does the following:
- Shrinks the thymus gland, which produces important immune cells called T-cells
- Suppresses white blood cell activity, weakening your ability to fight off pathogens
- Reduces the production of immunoglobulins, antibodies that help you neutralise viruses and bacteria
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Promotes inflammation, which creates immune confusion—your body stays “on alert” and becomes less efficient at handling real threats
Eventually, your immune defences are worn thin. You may notice that you’re picking up every bug going around, recovering slowly from infections, or experiencing flare-ups of chronic issues like cold sores, eczema, or autoimmune symptoms.
And it’s not just physical. Chronic stress also affects your sleep, digestion, and mood, creating a vicious cycle that further taxes your immune system.
This is why at ADHD Naturopathic Clinic, we never treat the immune system in isolation. If stress is a major factor in your life—and for most of us, it is—then supporting your adrenals and nervous system is just as important as taking immune-boosting herbs.
Gut Health: The Unsung Hero of Immune Function
Your gut isn’t just a food-processing tube—it’s the command centre for your immune system. In fact, around 70–80% of your immune cells live in and around your gastrointestinal tract. That means what happens in your gut doesn’t stay in your gut—it influences everything from your skin to your sinuses to your energy levels.
When your gut lining is healthy, it acts as a strong barrier, allowing nutrients in while keeping harmful substances out. But when it becomes inflamed or “leaky” (a condition known as intestinal permeability), things start to go wrong.
Instead of staying contained in the digestive tract, toxins, bacteria, yeast, and undigested food particles can pass through the gut lining into the bloodstream. This triggers your immune system to go on high alert, launching inflammatory responses and potentially mistaking harmless things—like food proteins—for invaders.
Over time, this can lead to:
- Chronic low-grade inflammation
- Food sensitivities and intolerances
- Autoimmune flares
- Frequent infections, especially respiratory or skin-related
- A constant feeling of being “off” without any obvious diagnosis
Your gut microbiome—the trillions of bacteria that live in your digestive tract—also plays a critical role. These microbes train your immune system, produce vitamins (like B12 and K), and help regulate inflammation. But if your microbiome becomes imbalanced (a state called dysbiosis) due to poor diet, antibiotics, stress, or toxins, your immune defences can weaken dramatically.
You may notice:
- Chronic sinus infections or hay fever-like symptoms
- Eczema, acne, or unexplained skin flare-ups
- Feeling puffy or inflamed after eating
- Constipation, bloating, or irritable bowels
- Increased reactivity to foods, chemicals, or environmental triggers
We often find that immune support must begin with gut healing—clearing out pathogens, restoring beneficial bacteria, and repairing the gut lining with targeted herbal and nutritional support. When the gut is nourished and sealed, the immune system becomes calmer, more responsive, and far less reactive.
Chronic Infections: The Hidden Drain on Your Immune System
Not all infections come with fevers, sore throats, or runny noses. In fact, many people carry chronic, low-grade infections that fly under the radar for years—quietly exhausting their immune systems.
Viruses like Epstein-Barr Virus (EBV) and Cytomegalovirus (CMV), bacterial infections such as Lyme disease, or fungal imbalances like Candida overgrowth can all linger in the body long after an initial infection. Instead of clearing out completely, these pathogens may go dormant and periodically reactivate—keeping the immune system in a constant state of low-level alert.
This continuous immune stimulation can lead to:
- Immune fatigue – where your white blood cells become less responsive over time
- Inflammation and oxidative stress – which further weakens tissue repair and immune regulation
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Autoimmunity – as the immune system becomes confused and starts attacking healthy tissue
What’s tricky is that these chronic infections don’t always show up as traditional “sick” symptoms. Instead, you might notice:
- Persistent fatigue that doesn’t improve with rest
- Joint pain or muscle aches with no obvious cause
- Brain fog, forgetfulness, or poor concentration
- Increased sensitivity to foods or chemicals
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Frequent viral reactivations (e.g. cold sores, shingles, or sore throats)
For some, these infections are triggered or reactivated by stress, poor gut health, or nutrient deficiencies, which are already straining the immune system.
We often explore functional testing to identify signs of chronic infections—such as antibody levels, immune markers, or stool tests for yeast and bacterial imbalances.
Nutrient Deficiency: When Your Immune Cells Can’t Do Their Job
Your immune system is like an army—but even the best-trained soldiers can’t fight without supplies. Every immune cell needs specific nutrients to develop, activate, and perform its defence duties. And when those nutrients run low, your body’s ability to respond to infection or inflammation drops dramatically.
Some of the key nutrients for immune strength include:
- Zinc – essential for immune cell production and communication
- Vitamin C – a potent antioxidant that helps fight off viruses and support white blood cell function
- Vitamin D – regulates immune response and lowers inflammation
- Vitamin A – supports mucosal barriers like the lungs, sinuses, and gut
- Selenium – helps the body create antioxidant enzymes that neutralise free radicals
- Iron – needed for energy and oxygen transport, as well as immune activation
- B Vitamins – crucial for stress regulation, energy production, and immune resilience
Even if you're eating a good diet, many people still end up deficient—and here’s why:
- Poor digestion and low stomach acid - If you’re not breaking down your food properly, you’re not absorbing those nutrients effectively. Low stomach acid, often overlooked, can reduce your body’s ability to extract zinc, iron, calcium, and B12 from food.
- Chronic stress - Stress doesn’t just make you feel drained—it burns through nutrients, especially B vitamins, magnesium, and vitamin C. This leaves your body depleted at a time when it needs even more support
- Genetic mutations - Conditions like MTHFR, CBS, or other methylation-related mutations can impact how your body uses key vitamins like folate, B12, and B6. Even if you're eating plenty or taking supplements, your cells might not be able to utilise those nutrients properly without targeted support.
- Medications - Certain medications—especially antacids, proton pump inhibitors, antibiotics, and even the Pill—can interfere with nutrient absorption or speed up depletion. Long-term use may quietly erode your nutrient reserves.
If your immune system seems sluggish, or you're frequently rundown despite taking supplements, it could be a sign of deeper nutrient imbalances. We use tools like functional blood testing, genetic analysis, and symptom tracking to uncover exactly where your nutrient reserves need a boost—then build a personalised plan using herbs, minerals, and targeted nutrition to restore your immune function naturally.
Toxic Load & Environmental Toxins: Hidden Barriers to Immune Health
You may be eating well and taking immune-supporting herbs, but if your body is burdened by toxins, your immune system could still be struggling in the background.
Exposure to heavy metals like mercury, lead, aluminium, and cadmium—as well as pesticides, mould mycotoxins, and everyday chemical pollutants (such as those in plastics, cleaning products, and cosmetics)—can have a profound effect on immune function.
These toxins don’t always cause immediate symptoms, but over time they:
- Increase oxidative stress, which damages cells and tissues
- Disrupt the normal communication of immune cells, reducing your ability to fight infection
- Impair detoxification pathways, especially in the liver
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Interfere with hormone signalling, especially cortisol and thyroid hormones, which are vital for immune balance
Even low-level, chronic exposure can lead to fatigue, brain fog, frequent infections, skin issues, allergies, and even autoimmune flare-ups.
We use HTMA (Hair Tissue Mineral Analysis) to assess your mineral levels and detect possible toxic metal exposure. Unlike blood tests, which show what's currently circulating, HTMA reflects what’s been stored or excreted over time—offering a window into your long-term toxic burden. This can help identify hidden blocks to healing that are impairing your immune resilience.
Once identified, we support detoxification with a combination of herbs, minerals, antioxidants, and liver support tailored to your unique results.
Other factors can also impact your Immune System like:
- Sleep Deprivation - Sleep is when the body carries out immune surveillance and repair. Poor sleep (or insomnia) lowers white blood cell activity and increases inflammation. Even just a few nights of disrupted sleep can reduce your ability to fight off infections or recover quickly.
- Genetic Polymorphisms - Certain genetic variations - like MTHFR, COMT or GST mutations - can impact detoxification, methylation, and antioxidant pathways. This can lead to a build-up of toxins or inflammation, making the immune system work harder and less efficiently. For example, poor methylation can reduce immune cell formation and repair.
- Chronic Inflammation & Autoimmunity - Low-grade, chronic inflammation (from food sensitivities, insulin resistance, or hidden infections) puts the immune system in a constant state of reactivity. Over time, this can lead to immune dysfunction or even autoimmune conditions, where the body mistakenly attacks its own tissues.
- Lack of Sunlight & Vitamin D - Vitamin D isn’t just a nutrient—it’s a hormone-like regulator of immune function. Low levels (especially during winter) are linked to increased infections, autoimmunity, and poor recovery. Many people with recurring colds or chronic fatigue have unrecognised vitamin D deficiency.
- Lifestyle Factors - Excessive alcohol, smoking, lack of movement, or overtraining can all deplete the immune system. These habits contribute to oxidative stress, reduce detox capacity, and lower lymphatic circulation—all impairing your immune resilience.
Bringing It All Together: Supporting Your Immune System at the Root Cause
Your immune system is incredibly complex, influenced by many interconnected factors—from stress and gut health to nutrient levels, hidden infections, toxins, and genetics. Understanding these root causes is the first step toward real, lasting improvement.
At ADHD Naturopathic Clinic, we take a holistic, personalised approach to uncover what’s truly driving your symptoms. Through comprehensive testing and in-depth consultations, we develop tailored herbal and nutritional plans designed to restore balance, strengthen your immune resilience, and improve your overall wellbeing.
If you’re tired of quick fixes and want to address your health at the source, book a consultation with us today to start your journey toward better immune health.