Experiencing deep, unrelenting exhaustion that no amount of sleep seems to fix is a truly isolating experience. If this sounds familiar, you are not alone. Chronic Fatigue Syndrome (CFS), also known as Myalgic Encephalomyelitis (ME), is a complex and often misunderstood condition.
In Functional Medicine, we’ve found that while the fatigue is the most visible symptom, it is almost always the result of several underlying issues. The good news is that we have helped and supported many patients to get and stay well by identifying and addressing these root causes. Recovery is possible.
What is Chronic Fatigue from Our Perspective?
Traditional medicine often defines ME/CFS by a set of symptoms (e.g., severe fatigue lasting over six months). While this helps to describe the symptom, it fails to offer solutions or insight into the root cause of the fatigue. In Functional Medicine, we view chronic fatigue not as a single disease, but as a complex web of dysfunction affecting multiple systems in the body.1
These symptoms are the body’s alarm system going off. A sign that the essential processes responsible for producing energy, managing stress, maintaining hormones or fighting off infections have become overwhelmed or depleted. Our goal is to ask “Why?” did the energy crash happen, and what can we do to rebuild resilience and functionality?
Key Symptoms to Recognise
While the hallmark symptom is persistent fatigue not relieved by rest, ME/CFS often involves a cluster of other debilitating issues which may include:
- Post-Exertional Malaise (PEM) – This is the worsening of symptoms after (sometimes minimal) physical or mental exertion. The onset can be delayed by 24–48 hours, and a ‘crash’ can last for days.
- Unrefreshing Sleep – This is waking after a full night of sleep feeling as tired as when you went to bed.
- Cognitive Difficulties (“Brain Fog”) – Trouble with memory, focus, concentration, and word recall.
- Orthostatic Intolerance – Dizziness, light-headedness, or a fast heartbeat when moving from sitting or lying down to standing.
- Widespread Pain – Unexplained muscle or joint aches (sometimes referred to as fibromyalgia).
- Immune Issue – Recurring infections, sore throats or tender lymph nodes.
Uncovering the Root Cause Reasons
Instead of concentrating on just treating individual symptoms, our approach focuses on identifying the unique combination of factors underlying the energy depletion. We often find issues in one or more of these areas –
1. Mitochondrial Dysfunction
Your mitochondria are tiny powerhouses in every cell in your body, responsible for creating energy as the molecule ATP. When mitochondrial function becomes impaired due to oxidant stress, chronic inflammation, lack of essential micronutrients, loss of essential thyroid hormones or exposure to toxins, energy production can plummet.
2. Chronic or Reactivated Infections
ME/CFS often starts after an acute illness and can be linked to abnormal chronic immune responses and re-activation of previously dormant infections when the immune system is under stress or suppressed. Functional Medicine testing helps us to investigate whether chronic bacterial, viral or fungal infections are underlying the huge array of symptoms that many patients with CFS experience alongside the fatigue. Common culprits include:
- Viral Infections: Epstein-Barr Virus (EBV), Herpes viruses (HHV-6 and HSV 1&2) and Cytomegalovirus (CMV).
- Yeast Overgrowth: Candida and many other species of yeasts can colonise the gut, nasal passageways, skin and lungs, leading to metabolic disturbance, release of mycotoxins and systemic illness.
- Chronic Bacterial Infections: Lyme Disease (Borrelia) and associated co-infections (including Babesia, Bartonella and Rickettsia).
3. Gut Health Problems
Gut dysfunction can lead to problems with digestion and absorption of essential micronutrients (low iron and B12 are especially important for energy production, and absorption can frequently be disrupted in CFS patients). If you can’t absorb the building blocks of energy, your body can’t perform.
‘Leaky gut’ (increased intestinal permeability) can lead to undigested food and pathogens entering the bloodstream around the gut and trigger harmful chronic immune responses, leading to an increase in food sensitivities and autoimmunity.
Dysbiosis (an imbalance of beneficial and overgrowth harmful gut microbes) can lead to high levels of inflammation that can occupy immune system and prevent normal protective responses to invading pathogens.
4. Stress Hormone Dysregulation
A history of chronic stress or trauma (due to both psychological or physical causes), chronic inflammation and toxicity can lead to abnormal production of the stress hormone cortisol. This is commonly referred to as adrenal dysfunction and it can cause problems with immune system functioning, digestion, sleep, mood and even blood pressure and fluid balance.
If the body is forced to exist in a high adrenaline state for a long period without rest (‘the fight or flight response’), there will be problems with anxiety, sleep deprivation and loss of normal digestion. Ultimately, this condition is not sustainable over the long term and we see the appearance of burnout and crashes with extreme exhaustion due to low cortisol states which follow.
5. Environmental Toxin Exposures
Exposure to toxins, such as heavy metals, mould/mycotoxins and others can place a huge burden on the body’s detoxification pathways. Toxins can have multi-system effects, causing damage to hormone production, reducing energy production, suppressing the immune system, and causing loss of chemical processing capacity (often leading to multiple chemical sensitivity).
Hope and the Path to Recovery
We want you to know that there is tremendous hope and that recovery is a tangible reality.
We have seen time and again that by methodically peeling back the layers and addressing the individual and inter-connecting root causes, the body can be restored back to a state of balance and sustained energy production.
Each path will be unique, focusing on targeted support for your gut health, immune system, energy pathways, and detoxification capacity.
Key Things to Recognise and How to Get Help
| Area | What to Recognise | How Functional Medicine Can Help |
| Pacing | Recognise your energy limits and never push through PEM. This is the most crucial step in preventing a crash. | We help you to learn to listen to your body and track data (such as HRV), to identify your current true capacity for energy expenditure. This can help you with pacing and with careful, safe expansion of activity when it’s safe to do so. |
| Testing, Not Guessing | General blood tests often miss the deeper issues (many of our sick CFS patients are told it’s all psychological because NHS tests are normal). | We utilise advanced lab testing for in-depth analysis of nutritional status, gut function and dysbiosis testing, hormonal production and metabolism, identification of chronic infection, toxin analysis and detox capacity assessment. |
| The “Why” | Realise that your fatigue is not simply a matter of poor willpower or lack of motivation. | We provide a safe, non-judgmental space to explore your full health story. From your genetics to your life events, to uncover your personal “why.” |
Evidence Base and Research
The Functional Medicine approach is supported by a growing body of scientific literature that explores the underlying biological mechanisms of ME/CFS.
- Mitochondrial Dysfunction – Research highlights the role of impaired cellular energy production in the pathology of ME/CFS (e.g., Studies on supplements like CoQ10 and B12 have shown benefits for fatigue and quality of life in some patients).
- Infections & Immune System – Studies consistently show immune system abnormalities, including decreased function of natural killer cells and links to persistent viral re-activation (e.g., Epstein-Barr Virus).
- The Gut-Brain Axis – Research confirms that gut dysbiosis and inflammation are common in ME/CFS patients and can contribute to many symptoms, including brain fog, mental health issues and pain.
Ready to Start Your Journey Back to Wellness?
We have supported thousands of patients to reclaim their energy and return to living a full life again. We believe in your ability to get better.
If you are tired of simply managing symptoms and are ready to explore the deeper, root causes of your chronic fatigue, the first step is a conversation with our team.
Book a conversation with our Treatment Planning Team today to discuss your health history and learn how a personalised Functional Medicine plan can help you get well and stay well.
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