How Chronic Stress Affects Your Body: Hormones, Digestion, Immunity & Mood

Chronic stress doesn’t just affect how we feel — it disrupts how the body functions at every level. From hormones and digestion to mood, immunity and sleep, long-term stress can quietly rewire the nervous system and create the conditions for deeper illness. In this article, we explore how stress affects the body, why so many symptoms are rooted in nervous system imbalance, and how to begin rebuilding resilience using natural, body-led strategies.

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Stress has become the backdrop of modern life — so familiar that most people don’t even notice it’s there. It shows up as a racing mind, shallow breathing, poor sleep, digestive issues, fatigue, low mood, or a constant sense of urgency. But underneath these surface symptoms lies something deeper: a nervous system stuck in overdrive.

While the occasional stressful event is a normal and even useful part of being human, chronic stress is something else entirely. When the body doesn’t get the chance to return to rest, the stress response becomes dysregulated. Over time, this leads to imbalances across nearly every system in the body — from hormone disruption to digestive shutdown, immune suppression, and inflammation in the brain.

Mental health symptoms are often the first sign that something’s not right. Anxiety, depression, insomnia, and brain fog can all trace back to the biochemical effects of long-term stress. And yet, most conventional responses still focus on managing the symptoms — with medications like SSRIs — rather than exploring what’s driving them in the first place.

This article explores what stress really does inside the body, why it’s often the missing link in persistent health issues, and how to begin rebuilding resilience through practical, natural steps. From gut health and neurotransmitters to nutrition, adaptogenic herbs, and trauma-informed practices, the goal is simple: to help you understand your body’s stress response — and learn how to support it.

Because stress may be common, but that doesn’t make it harmless. And the sooner we recognise its effects, the sooner we can start reversing them — naturally and sustainably.

Understanding the Stress Response — What Happens in the Body?

The human stress response was designed for survival. It’s an ancient biological mechanism that prepares the body to face immediate danger — speeding up the heart, sharpening the senses, and releasing a cascade of hormones like adrenaline and cortisol. In the short term, it’s incredibly effective. But in today’s world, the threat isn’t a lion in the grass — it’s a relentless mix of deadlines, social pressure, trauma, poor sleep, and overstimulation. And the stress response doesn’t know the difference.

When stress becomes chronic, the brain’s limbic system — particularly the amygdala and hypothalamus — stays activated. This keeps the nervous system locked in a state of hyper-vigilance, known as sympathetic dominance. Cortisol levels remain elevated, and the body begins to prioritise survival over everything else.

That’s when the knock-on effects begin:

• Digestion slows down, as blood is diverted away from the gut — leading to bloating, IBS symptoms, or nutrient malabsorption

• Thyroid function can drop, affecting metabolism, temperature regulation, and energy levels

• Sex hormones like oestrogen, progesterone and testosterone are disrupted, which can influence everything from mood to fertility to PMS

• Neurotransmitter balance shifts, with cortisol and inflammation interfering with the production of serotonin and dopamine — key chemicals for mental wellbeing

• The immune system becomes suppressed, leaving the body more vulnerable to infections and chronic inflammation

At first, this might show up as fatigue, sleep disturbance, or mood changes. But over time, the cumulative effect of stress touches every major system — creating the conditions for more serious long-term issues.

Understanding this physiology is key. It shows us that mental health symptoms aren't “all in your head.” They’re often rooted in a real, measurable imbalance in the body — one that can be addressed, supported, and gradually brought back into balance.

How Chronic Stress Alters Digestion, Hormones and Immunity

Chronic stress isn’t just something we feel — it’s something the body has to compensate for every single day. Over time, this internal burden disrupts the body’s most vital systems: digestion, hormonal regulation and immune resilience.

At first, these changes can be subtle. But as stress becomes prolonged, the body begins to shift into a state of survival that touches nearly every part of our physiology:

• Digestion slows down. Blood is redirected away from the gut, reducing enzyme output and impairing nutrient absorption. Bloating, discomfort and IBS-like symptoms often follow — even in people eating a balanced diet.

• Hormones become dysregulated. Elevated cortisol suppresses thyroid function and interferes with the balance of sex hormones like oestrogen, progesterone and testosterone. This can contribute to fatigue, PMS, irregular cycles, low libido and stubborn weight gain around the middle.

• The immune system weakens — or overreacts. At first, cortisol suppresses immune activity, leaving you more vulnerable to infections. Over time, chronic inflammation builds, which can worsen autoimmune conditions and increase systemic sensitivity.

• Neurotransmitter balance shifts. Serotonin, dopamine and GABA — the brain chemicals most associated with mood, focus and emotional resilience — are depleted when stress is sustained. This contributes to anxiety, depression, and sleep disturbance.

Individually, each of these issues can be challenging. But when they’re happening simultaneously — layered on top of one another — they create the kind of health picture that’s often dismissed as “just stress” when it’s actually the beginning of real physiological breakdown.

Recognising these patterns is the first step toward reversing them. Once you understand what’s happening in the body, you can begin to support it — not by suppressing the symptoms, but by restoring balance from the root.

Why SSRIs Miss the Root Cause of Stress-Driven Illness

For many people struggling with anxiety, low mood or emotional overwhelm, the first stop is often a GP appointment — and the most common outcome is a prescription for antidepressants, particularly SSRIs (selective serotonin reuptake inhibitors). While these medications can offer short-term relief, especially during acute emotional crises, they don’t address the underlying physiology of chronic stress.

SSRIs work by increasing the availability of serotonin in the brain. But if the body is depleted — if the gut isn’t producing enough raw serotonin to begin with, or if chronic cortisol elevation is disrupting the brain’s chemical signalling — then simply recirculating what’s already there may have limited long-term benefit.

What’s more, many people prescribed SSRIs are also dealing with symptoms like IBS, hormonal disruption, fatigue or insomnia — all of which are signs that the nervous system and the endocrine system are under strain. In these cases, medication may dull the emotional edges, but it does little to restore balance where the disruption began: in the stress response itself.

That’s not to say medication has no place. For some, it can be a useful bridge during an intense season of life. But we need to widen the lens. Because real, sustainable recovery — especially from stress-related mental health conditions — requires more than symptom management. It requires supporting the body as a whole: calming the nervous system, nourishing the gut-brain axis, and restoring the building blocks of healthy neurotransmitter and hormone function.

This is where holistic approaches shine. When we work with the body’s natural systems — rather than overriding them — true resilience can be rebuilt.

The Gut–Brain Connection — Why Serotonin Starts in the Stomach

It’s often assumed that serotonin — the brain’s “feel good” chemical — is something produced primarily in the head. But in reality, over 90% of serotonin is made in the gut, not the brain. This is why digestive health plays a central role in mental health, and why chronic stress, poor diet, and disrupted microbiome balance can have such a profound impact on mood.

The gut and the brain are in constant communication via the vagus nerve, forming what’s known as the gut–brain axis. When the digestive system is functioning well, this pathway supports healthy neurotransmitter production, balanced inflammation levels, and overall emotional stability. But under chronic stress, the gut environment begins to break down.

Cortisol suppresses digestive enzymes and slows motility. Stress hormones alter the diversity of beneficial bacteria in the gut, allowing more opportunistic microbes to thrive. Over time, this imbalance — known as dysbiosis — can interfere with serotonin synthesis, compromise the integrity of the gut lining, and further increase systemic inflammation.

The result is a self-reinforcing loop: stress disrupts gut health, poor gut health worsens mental wellbeing, and symptoms continue to accumulate.

This is why nutritional and digestive support is so crucial when addressing stress-driven mental health concerns. By supporting the gut environment — through a combination of whole foods, targeted nutrients, and microbiome-friendly herbs — we begin to restore the body’s natural ability to self-regulate.

Mental wellness doesn’t start in the mind alone. It starts with a healthy, nourished foundation — one that the gut plays a central role in building.

Rebuilding Resilience — Nutrients, Herbs and Lifestyle Strategies That Support the Nervous System

Once we understand how stress affects the body, the path forward becomes clearer. The goal isn’t to eliminate all stress — that’s neither realistic nor necessary. The goal is to build resilience: to strengthen the nervous system so it can respond, recover and rebalance without getting stuck in survival mode.

This begins with nourishment. The nervous system depends on a steady supply of key nutrients to regulate mood, calm inflammation and maintain hormonal stability. When the body is depleted — often the result of long-term stress, irregular eating, or poor gut absorption — emotional and physical symptoms become harder to manage.

The most important building blocks for a healthy stress response include:

• Magnesium – Known as “nature’s tranquilliser,” magnesium supports muscle relaxation, nervous system regulation, and adrenal function. Found in leafy greens, pumpkin seeds and dark chocolate; often best supplemented (400mg at night).

• B vitamins – Essential for neurotransmitter production and energy metabolism. Vitamin B6 supports serotonin synthesis, while B5 nourishes the adrenal glands. Found in avocados, bananas, oats and wholegrains; best taken as a B-complex for synergy.

• Zinc – Supports hormone balance, mood regulation and immune resilience. Often depleted under stress. Found in pumpkin seeds, lentils and seafood.

• Omega-3 fatty acids – Help reduce inflammation in the brain and body, and support cognitive and emotional health. Found in oily fish like sardines and salmon; supplementation may be needed, especially for teenagers and those with low intake.

• Adaptogenic herbs – These support the body’s ability to adapt to stress without overstimulation or sedation. Ashwagandha and holy basil are two of the most gentle and widely used. Oat straw (Avena sativa) is another calming tonic used both in food and herbal formulas.

But nutritional support is only one part of the picture. Lifestyle plays a powerful role in restoring nervous system resilience. Regular movement, consistent sleep rhythms, time outdoors, and trauma-informed practices like somatic therapy, EFT (emotional freedom technique), or breathwork can all help recalibrate the system at a deeper level.

There is no one quick fix — but there is a path. And it begins by choosing, day by day, to give your body what it needs to feel safe again.

The Path to Healing — Why Mental Health Recovery Requires a Whole-Body Approach

There’s no one-size-fits-all solution to healing from chronic stress, and certainly no magic pill for restoring mental health. What’s needed is a shift in perspective — from symptom suppression to system support. Because the mind doesn’t function in isolation, and mental health is never just about brain chemistry. It’s about the entire terrain of the body.

True resilience is built slowly, by nurturing the foundations that support emotional wellbeing from the inside out: balanced blood sugar, strong digestion, a regulated nervous system, restorative sleep, and meaningful connection. These aren’t optional extras — they are the conditions under which healing becomes possible.

It also means recognising that many people — especially young people — aren’t broken. They are overwhelmed, depleted, and living in a world that rarely gives them the tools or time to recover. And while medication can sometimes offer a lifeline in crisis, long-term recovery calls for something deeper: nourishment, safety, education, and support.

At EarthWise, our approach is always whole-body, whole-person, and rooted in the wisdom of the body itself. When you work with that wisdom — instead of overriding it — you open the door to true, sustainable healing.

The nervous system can relearn safety. The gut can rebuild. The mind can come back into balance.

And it all begins with a choice: to understand what stress is doing in the body — and to begin doing something different in response.