Functional Pathology
Online consultations are also available
"Bloods unremarkable."
And yet here you are. Foggy. Fatigued. Slower than you used to be. Reactive in ways you never were. Carrying a body that does not feel like a body that is within normal limits.
"Around 85 to 90 percent of patients with cognitive decline can reverse it, when we do the work. But you have to know what's actually driving it. And standard tests aren't asking that question."
Jo Grabyn, Clinical Naturopath and ReCODE 2.0 Certified Practitioner, founder of Bounce Matters
This page explains what functional pathology actually is, the testing approach we use across every condition we treat at Bounce Matters — whether you are here for cognitive decline and dementia prevention, concussion and brain injury recovery, brain fog, mood and cognitive resilience, or complex chronic and neurological symptoms.
Functional pathology is not a condition. It is a method. And it is the layer of investigation that explains why so many patients with real symptoms keep being told "everything looks fine."
I want to be clinically honest with you in both directions — about what functional pathology can reveal, and about where parts of it have been over-claimed in the industry. Both honesties matter.
Why your tests keep coming back "normal"
Standard blood tests routinely come back "normal" in patients with real symptoms because reference ranges are designed to detect disease, not dysfunction.
The standard panel is built to identify people who are sick now. It is not built to identify people whose biochemistry is drifting toward illness over the next five to twenty years. There are three structural reasons for this.
Reason 1: Reference ranges are population-based, not optimal-based
The "normal range" for a given marker is typically set at plus or minus two standard deviations from the population mean. By definition, around 95% of the population sits inside it — and that population includes a great many people who are functioning poorly. If half the country has subclinical thyroid dysfunction, the "normal" range will include subclinical thyroid dysfunction. That is how the maths works.
Why "normal" isn't always optimal
Range
— still symptomatic
— still symptomatic
Reason 2: Standard panels are built for frank disease, not sub-clinical dysfunction
TSH alone is the canonical example. It is excellent for catching someone with overt hypothyroidism. It is silent on the kind of tissue-level thyroid imbalance that produces brain fog, fatigue, and dry skin in a person whose TSH is technically inside the lab range.
Reason 3: The system has bandwidth limits
A standard general practice consultation is built to handle high-volume care across a vast range of presentations. The Medicare-funded pathology panel, as described by Healthdirect Australia, is necessarily focused on rational limits. A 10-minute consultation cannot reasonably synthesise the multi-system, multi-year picture that complex chronic patients usually bring.
This is not a criticism of GPs. It is a description of a system that is optimised for detecting disease in a general population — and a description of the gap that opens when the patient sitting in front of the GP has persistent unexplained symptoms that don't meet diagnostic criteria for any one named condition. That gap has a name in the literature. They call it the diagnostic odyssey.
The diagnostic odyssey is real and expensive
The diagnostic odyssey is real, documented, and 7.6 times more expensive than the equivalent care for matched controls. A 2025 study in the Orphanet Journal of Rare Diseases quantified what most patients with chronic unexplained symptoms already know in their bones.
| Group | Direct Healthcare Cost |
|---|---|
| Patients on a diagnostic odyssey | €26,999 (~AUD 43,900) |
| Matched controls | €3,561 (~AUD 5,800) |
| Difference | 7.6× higher cost for the undiagnosed group |
Two pathways. Two timelines.
What happens between first symptoms and a real answer.
Standard GP Pathology
Symptoms begin
"Bloods unremarkable"
2–4 years of symptoms
Multiple specialists, no clear answers
Diagnosable disease
Criteria finally met
Functional Pathology
Symptoms begin
Targeted investigation starts
6–12 weeks
Drivers identified, plan in place
Trajectory changed
Function improving
"By the time most of my patients reach me, they've spent two to four years and tens of thousands of dollars getting the same answer — nothing's wrong. They're not making it up. They're being asked the wrong question."
Jo Grabyn, BHSc (Nutritional Medicine), Bounce Matters, Manly
This is not a failure of medicine. It is a description of a system that diagnoses categorical disease well and characterises pre-disease dysfunction less well. Functional pathology exists to fill that specific gap. And like any clinical tool, it is only as useful as the clinician using it.
What standard GP pathology covers well
Two panels. Two questions. One patient.
Standard GP Pathology
"Do you have a disease?"
Frank anaemia and iron deficiency
Diagnosed thyroid disease (TSH)
Diabetes and prediabetes
Significant infection and inflammation
Catches the disease
Functional Pathology
"Where is the dysfunction?"
Sub-optimal thyroid function (T3/T4/Abs)
Mycotoxin exposure and CIRS markers
Gut barrier and microbiome dysbiosis
Methylation and mitochondrial function
Characterises dysfunction
Standard GP pathology and functional pathology are complementary, not competitive
Standard GP pathology, properly ordered, is excellent at detecting frank disease across most major systems. Before I describe what functional pathology adds, I want to be clear about what your GP's panel does brilliantly — because the argument I'm making is that the two are complementary, not competitive.
What standard GP pathology reliably identifies
- Frank anaemia, advanced kidney disease, advanced liver disease
- Diagnosed thyroid disease (typically via elevated TSH)
- Diabetes (HbA1c, fasting glucose)
- Most acute infections (FBC, CRP)
- Common autoimmune patterns (ANA, RF, anti-CCP, though with limits)
- Lipid risk
- Basic electrolyte and renal function
- Most haematological cancers and many solid tumours via cascade testing
If you have any of those, you want a GP, you want them now, and you want their pathology panel — not a $1,200 functional workup.
"I never want a patient to choose between their GP and their functional workup. We work alongside each other. We make educated decisions together. The GP catches the disease. The functional workup catches what's driving the dysfunction underneath it."
Jo Grabyn, in clinical practice with referring GPs across Sydney
Where the standard panel typically stops
Standard pathology, by design, often does not investigate:
- Sub-optimal thyroid function (free T3, reverse T3, antibodies typically require specific requests)
- Iron deficiency in the 30–50 ng/mL ferritin range where many patients are symptomatic
- Methylation pathway function (folate metabolism, homocysteine)
- Inflammation patterns beyond CRP
- Insulin resistance (fasting insulin is rarely run unless requested)
- Comprehensive nutrient status (active B12, RBC magnesium, zinc, copper, selenium)
- Vitamin D in clinically optimal rather than deficiency ranges
- Mycotoxin exposure
- Heavy metal status
- Gut microbiome and barrier function
- Mast cell mediators
- Autonomic and neurotransmitter function
That is not a list of things every GP should be running. It is a description of where the standard panel stops — and where, for some patients with persistent unexplained symptoms, the next layer of investigation may begin.
In clinic: a case
Wendy — de-identified, used with permission
Wendy was diagnosed with Alzheimer's the week before her 52nd birthday. For two years she had been told her cognitive symptoms were menopause. Her standard pathology was unremarkable.
Functional pathology — urinary mycotoxins, an extended autoimmune panel, and a careful exposure history — confirmed old workplace mould exposure as the dominant driver. Whole-family testing then identified shared exposure markers in her husband and adult children. Treating the actual driver changed the trajectory of her case.
Her standard tests had been telling the truth about disease. They had simply not been asked about dysfunction.
What functional pathology adds (when it's used well)
Functional pathology is not a brand of test. It is a clinical lens.
Used well, it can:
- Identify modifiable drivers of symptoms before they become disease
- Stratify priorities when multiple drivers are likely (which is the usual situation)
- Direct treatment with much more precision than empirical trial and error
- Track response over time using objective markers
Used poorly, it can:
- Generate large bills for tests that don't change anything
- Identify 'abnormalities' with no clinical significance
- Encourage treatment of numbers rather than patients
- Promise certainty that the underlying science doesn't support
Both versions exist in this industry. The difference is the clinician.
"Test, don't guess. But also, don't test for the sake of testing. Every panel I order has to answer a clinical question I can't answer another way — and it has to change what we do next."
Jo Grabyn, on her testing philosophy at Bounce Matters
The eight categories we use
What we actually test, and why
Blood Chemistry
(Extended)
Comprehensive
Stool Analysis
Cortisol Pattern
(DUTCH)
Methylation
Genetics
Mycotoxins &
CIRS
Heavy
Metals
Autoimmune
Workup
Organic
Acids
The eight categories of functional pathology used at Bounce Matters
Category 1
Comprehensive blood chemistry (extended panel)
An extended blood chemistry panel goes beyond the standard Medicare panel to include full thyroid function (TSH, free T3, free T4, reverse T3, thyroid antibodies), comprehensive iron studies (ferritin, serum iron, transferrin saturation), active B12 and folate, fasting insulin, HbA1c, full lipid panel with particle size where indicated, homocysteine, comprehensive metabolic panel, and inflammatory markers beyond CRP. This is the foundation of every workup. It is also the layer most likely to identify the quick wins — the ferritin at 28, the TSH at 3.8 with antibodies, the fasting insulin that explains the afternoon crashes.
Category 2
Comprehensive stool analysis
A comprehensive stool analysis maps the gut microbiome in detail — commensal bacteria, opportunistic pathogens, parasites, yeast, and markers of intestinal permeability and inflammation. The gut-brain axis is bidirectional. Gut dysbiosis, intestinal permeability, and microbiome imbalances can influence neurotransmitter production, inflammatory load, and cognitive function. Evidence base: The microbiome-gut-brain axis is one of the most active areas of current neuroscience research. The specific clinical interpretation of individual microbiome results is more complex than the marketing often suggests, but the broad clinical value of this panel in complex chronic presentations is well-supported.
Category 3
Salivary or urinary cortisol pattern (DUTCH or equivalent)
A diurnal cortisol pattern across 4–6 time points reveals HPA-axis function in a way a single AM cortisol on bloods never will. DUTCH (Dried Urine Test for Comprehensive Hormones) adds oestrogen and progesterone metabolite pathways, which can be useful in selected hormonal cases, particularly perimenopausal complexity. Evidence base: The diurnal pattern is well-evidenced. Metabolite pathway interpretation is more interpretive than diagnostic, and benefits from being read alongside symptoms and other markers, not in isolation.
Category 4
Methylation genetics and targeted polymorphisms
Methylation genetics are useful for explaining stubborn symptom patterns, but the clinical interpretation has been over-stated in mainstream functional medicine. The most relevant methylation markers — MTHFR C677T, MTHFR A1298C, COMT, MTRR, MTR — when read alongside homocysteine and active B vitamin status, can help explain certain patterns. Crucially, the US Centers for Disease Control is explicit: 'People with MTHFR variants can process all types of folate including folic acid, and should not avoid folic acid on that basis.' We use methylation genetics where it adds clarity to a specific case. We do not use it as a master switch or a justification for a generic supplement protocol.
Category 5
Mycotoxin and CIRS evaluation (when clinically indicated)
Mycotoxin testing is appropriate where there is a clear exposure history, a multi-system inflammatory presentation, and a positive Visual Contrast Sensitivity screen — not as a routine panel. If a patient has lived in a water-damaged building, has a constellation of symptoms suggesting Chronic Inflammatory Response Syndrome (CIRS), and a positive screen on the VCS test, then more detailed mycotoxin testing may be appropriate. A 2024 literature review in the Annals of Medicine and Surgery concluded that the Shoemaker Protocol is the treatment approach for CIRS with the most documented clinical evidence. We order this panel only when clinical signal is present. This is the most common driver we identify in our complex chronic and neurological symptoms cases.
Category 6
Heavy metals
Whole-blood heavy metals testing is appropriate where exposure history or symptoms suggest a toxic load. Provoked urine challenge testing is not a routine screen. Toxic metal exposure — particularly lead, mercury, and aluminium — has well-evidenced neurological consequences. A 2014 review in Interdisciplinary Toxicology describes the mechanisms, and a Journal of Alzheimer's Disease review summarises the evidence linking heavy metal exposure to Alzheimer's disease and related dementias. Appropriate testing depends on the exposure question: recent or ongoing exposure is best assessed via whole-blood metals. Provoked urine challenge is reserved for patients with clear exposure history and a clinical reason to investigate further.
Category 7
Autoimmune workup beyond ANA
Extended autoimmune panels are appropriate where history suggests autoimmune involvement, particularly rapid-onset cognitive symptoms, psychiatric symptoms, movement disorders, or seizures. Where the picture warrants it, an extended autoimmune panel may include ENA panel, anti-thyroid antibodies, coeliac antibodies, MOG-IgG, and NMDA-receptor antibodies. A 2022 JAMA Neurology study found that autoimmune encephalitis is frequently misdiagnosed as psychiatric illness or dementia. This is a panel that can change a diagnosis.
Category 8
Organic acids and mitochondrial function markers
Organic acids testing (OAT) provides a snapshot of mitochondrial function, neurotransmitter metabolism, gut dysbiosis markers, and nutritional status via urinary metabolites. It is a useful second-layer investigation in complex chronic presentations, particularly where fatigue, cognitive symptoms, and gut issues co-occur. Evidence base: The OAT has a meaningful evidence base in specific clinical contexts. A review by Dr Jennifer Horton provides a useful clinical perspective. It is not a screening tool for the general population.
Tests we do not routinely order
In the interest of clinical honesty, there are tests in this space that look impressive on a brochure and tell you almost nothing in clinic:
- Hair tissue mineral analysis for general screening
- IgG food sensitivity panels as an elimination guide
- Bioenergetic / Vega / Voll devices
- Live blood analysis
- Provoked heavy metal challenges as a routine screen
"I'd rather lose the sale than charge a patient for a test I don't believe in."
Jo Grabyn, Clinical Naturopath, Bounce Matters Sydney
How a proper functional workup is structured
A proper functional workup is a five-step sequence, not a panel of tests. At Bounce Matters, this is the Reveal phase of The ClearPath Method, and it precedes any treatment plan.
THE REVEAL PHASE — ClearPath Method
Intake
90-minute deep dive
Standard
Pathology
Catching overt disease
Functional
Tests
Characterising dysfunction
Synthesis
Connecting the dots
Phased
Plan
Targeted next steps
Every test must answer a clinical question we cannot answer another way
Comprehensive intake (~90 minutes)
Full picture, including symptom history with a timeline, exposures (environmental, occupational, residential), family history, lifestyle factors, sleep architecture, diet pattern, stress narrative, medication and supplement history, and previous testing and treatment. By the end of this appointment, the candidate drivers are already shortlisted.
Standard pathology (where it hasn't already been done thoroughly)
Often these are the missing pieces from the patient's existing record. Many cases are partly solved at this layer alone, before any functional testing is ordered.
Targeted functional pathology
Selected based on the picture, not a fishing exercise. The question for each panel is: 'What will this test tell us that we cannot learn another way, and how will the result change the plan?' If we can't answer that, we don't order it.
Synthesis appointment (30–45 minutes)
We walk through what was found, what it means, which drivers are operating in this specific case, and in what order to address them. This is the appointment where guesswork stops.
Phased treatment plan
The Reveal phase feeds into the rest of The ClearPath Method: Fuel (nutritional and metabolic foundations), Rebalance (gut, hormones, stress, sleep), Build (cognitive reserve and adjunct modalities), Stay on Course (long-term maintenance). Order matters.
What investment looks like
Functional pathology is generally not Medicare-rebatable. Most workups involve a meaningful out-of-pocket investment in 2026 in Australia — but the alternative is usually more expensive.
- Standard pathology that your GP requests for a clinical reason is typically bulk-billed
- Functional pathology — stool analysis, mycotoxin panels, methylation genetics, salivary cortisol patterns, OAT — is usually paid out of pocket
- Some private health funds offer partial rebates under "natural therapies" extras (confirm before testing)
- The exact figure depends on which panels are clinically indicated, and we do not order panels that are not indicated
You will hear the cost picture on a Discovery Call, before any testing is ordered. There are no surprises.
When functional pathology is right for you
It IS the appropriate next step when:
- Symptoms have been persistent for six months or longer
- Standard tests have been done thoroughly and have come back unremarkable
- The pattern is multi-system (cognitive, gastrointestinal, hormonal, immune, skin, mood)
- There is relevant exposure history (water damage, mould, heavy metals, persistent infections, post-viral onset)
- A diagnostic label has been given that doesn't seem to fit
- You are willing and able to invest in proper investigation and a multi-month plan
It is NOT the appropriate first step when:
- Symptoms are acute or new — your GP first, always
- A clear standard diagnosis exists and conventional pathways have not yet been adequately explored
- You are looking for a definitive single-test answer (functional pathology produces a picture, not a single answer)
- You cannot commit to a multi-month, multi-phase plan
- You are looking for a clinician who will simply confirm what you already believe
A closing thought
The patient with the folder of normal results is not making it up. They are receiving an answer to the wrong question.
The standard system, asking the question it was built to ask, is saying: "Do you have a diagnosable disease right now?" The honest answer in many cases of persistent complex symptoms is no — not yet, not by current criteria. That is not the same as being well.
The question that needs asking is different: "How is the system actually performing, and where is the dysfunction that is driving how you feel?" That question, properly asked through a thoughtful clinical history and targeted functional pathology, has an answer for most patients.
"This isn't a sentence. It isn't a given. Most of the patients who walk into my clinic foggy, fatigued and frustrated walk back out clear — but only because we asked the right questions first."
Jo Grabyn, BHSc, ReCODE 2.0 Certified Practitioner (Bredesen Protocol)
If you have made it this far, you are probably ready to start. The right next step is a Discovery Call. It is 30 minutes, complimentary, and it is the appropriate place to discuss your specific situation — what investigation would look like, what realistic outcomes are, and what the investment would involve. There is no pressure to commit on the call.
You have been asking a real question. You deserve a real investigation.
Frequently Asked Questions
What is functional pathology?
Functional pathology is a category of laboratory testing designed to investigate how well your body's systems are functioning, rather than only whether you meet criteria for a named disease. It typically includes extended blood chemistry, gut microbiome analysis, hormone metabolite mapping, methylation genetics, and exposure markers (mycotoxins, heavy metals). It complements, not replaces, standard GP pathology.
How is functional pathology different from standard blood tests?
Standard blood tests are designed to detect frank disease using population-based reference ranges. Functional pathology asks a different question: how is the system performing, and where is the dysfunction driving symptoms? Standard pathology catches the disease. Functional pathology characterises the dysfunction underneath it.
Why do my blood tests come back normal when I feel terrible?
Standard reference ranges are population-based, not optimal-based — meaning around 95% of the population sits inside the 'normal' range, including people who are functioning poorly. Standard panels are also designed to detect overt disease, not sub-clinical dysfunction. A TSH inside the lab range can still sit alongside symptomatic thyroid imbalance at the tissue level.
Is functional pathology covered by Medicare in Australia?
Functional pathology is generally not Medicare-rebatable. Standard pathology your GP orders for a clinical reason is usually bulk-billed. Functional pathology — comprehensive stool analysis, mycotoxin panels, methylation genetics, salivary cortisol patterns, organic acids testing — is paid out of pocket. Your private health fund may offer a partial rebate under 'natural therapies' extras. Always confirm cost before testing is ordered.
Which functional pathology tests are actually evidence-based?
The tests with the strongest current evidence are extended blood chemistry (including full thyroid and iron studies), comprehensive stool analysis, diurnal cortisol patterns, whole-blood heavy metals where indicated, urinary mycotoxins where clinical signal is present, and extended autoimmune panels in specific presentations. Tests we do not routinely order include hair tissue mineral analysis, IgG food sensitivity panels, bioenergetic devices, live blood analysis, and provoked heavy metal challenges as a routine screen.
How do I know if I need functional pathology testing?
Functional pathology is appropriate when your symptoms have been persistent for six months or longer, standard tests have been done thoroughly and come back unremarkable, the pattern is multi-system, and there is relevant exposure history or a diagnostic label that doesn't fit. It is not the right first step for acute new symptoms — see your GP first, always.
How long does a functional pathology workup take?
A complete Phase 1 functional workup at Bounce Matters typically takes 6–10 weeks from initial 90-minute intake to synthesis appointment, depending on which panels are ordered and laboratory turnaround times. Stool analysis is usually 2–3 weeks; mycotoxin panels 3–4 weeks; methylation genetics 4–6 weeks. Treatment then begins once results are synthesised together.
Related on jograbyn.com
Conditions where we apply this method
References
- Schuetz B, et al. The cost of the diagnostic odyssey of patients with suspected rare diseases. Orphanet Journal of Rare Diseases, 2025. PMC12065212
- Healthdirect Australia. Paying for diagnostic testing. 2024. healthdirect.gov.au
- US Centers for Disease Control and Prevention. MTHFR Gene Variant and Folic Acid Facts. 2025. cdc.gov
- Sazonova D, et al. MTHFR Gene Polymorphisms: A Single Gene with Wide-Ranging Clinical Implications. Genes, 2025. PMC12027316
- Jaramillo Polanco JO, et al. Chronic inflammatory response syndrome: a review of the evidence of the Shoemaker Protocol. Annals of Medicine and Surgery, 2024. PMC11623837
- Jaishankar M, et al. Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary Toxicology, 2014. PMC4427717
- Bakulski KM, et al. Heavy Metals Exposure and Alzheimer's Disease and Related Dementias. Journal of Alzheimer's Disease, 2020. PMC7454042
- Flanagan EP, et al. Autoimmune Encephalitis Misdiagnosis in Adults. JAMA Neurology, 2022. jamanetwork.com
- Horton J. Is the Organic Acids Test Worth It? Peace and Calm Health Functional Medicine, 2026. drjenniferhorton.com