“But my blood tests are normal…” So why don’t I feel well?
It’s a sentence I hear in clinic all the time. “My doctor said my blood tests are normal, but I know something isn’t right.” And sometimes, technically, they are normal.
The results sit within the laboratory reference ranges. Nothing has been flagged. There may be no obvious disease process showing up. But the person sitting in front of me is still exhausted. Their brain feels foggy. Their periods have changed. They’re gaining weight despite doing all the things they’ve always done. Their digestion isn’t right. They can’t recover from exercise. They’re losing hair, sleeping poorly or simply saying: “I don’t feel like myself.” This is where I think pathology becomes really interesting.
I love pathology. After 24 years in clinical practice, it remains one of my favourite tools because I don’t look at each result in isolation. I’m looking for the story the results tell when we put them together.
For me, it is a little like assembling a puzzle. One result may mean very little on its own. But put it beside five other results, the person’s symptoms, their health history, medications, diet, age, hormonal stage and previous pathology and suddenly a pattern can begin to emerge.
“Normal” does still matter! Of course reference ranges are extremely important. They help doctors identify disease and determine when further investigation or treatment may be needed. But being inside a reference range doesn't automatically explain why someone feels unwell.
I’m often interested in questions such as:
Has this marker changed significantly from your previous result?
Are several related markers moving together?
Is something technically within range but sitting at one end of it?
Does the result make sense alongside your symptoms?
What happens when we look at iron, B12, inflammation, glucose regulation and thyroid function together rather than separately?
That distinction is important. I’m not trying to diagnose disease from a “normal” result. I’m trying to understand the person in front of me and decide whether there are clues worth exploring further.
My favourite starting pathology - I use specialised functional testing when it is clinically useful, but some of the most valuable information in my clinic comes from relatively ordinary pathology.
These are some of the tests I find myself returning to again and again:
Full Blood Examination (FBE): There is so much information sitting in an FBE beyond simply asking whether someone is anaemic. Red and white blood cell patterns, haemoglobin, haematocrit, MCV, MCH, RDW, platelets and differential white cells can all contribute another piece to the clinical picture.
General Biochemistry: Liver enzymes, kidney markers, proteins, electrolytes and other biochemical markers give us a broad view of what is happening physiologically. I particularly like comparing these results over time rather than viewing one snapshot in isolation.
Iron Studies: Ferritin alone isn't the entire iron story. Depending on the situation, I want to see the broader pattern across ferritin, serum iron, transferrin and transferrin saturation and interpret this alongside the FBE and inflammatory markers.
Vitamin B12: Particularly relevant when someone presents with fatigue, neurological symptoms, dietary restriction or other risk factors. Sometimes B12 is also more useful when considered alongside folate, the FBE and homocysteine rather than as an isolated number.
Homocysteine: One of my favourite additional markers. It can add another dimension when considering B-vitamin status and metabolism and can also contribute to the broader cardiovascular risk conversation.
Vitamin D: Important across immune function, bone health and muscle function and something I commonly monitor when supplementation is being used rather than simply recommending vitamin D indefinitely.
ESR and hs-CRP: Different inflammatory markers that can help add context when inflammation is part of the clinical question. They don't tell us why inflammation is occurring, but they can tell us that further investigation or monitoring may be worthwhile.
HbA1c, fasting glucose + fasting insulin: I particularly like seeing these together. Glucose alone doesn't tell us how hard the body may be working to maintain that glucose. Looking at longer-term glucose exposure alongside fasting glucose and insulin can give us a much better metabolic conversation.
TSH: A very useful starting point for thyroid assessment. If the symptoms, history or TSH suggest we need to understand more, we can then consider whether a broader thyroid assessment is appropriate.
ANA: This is not a general wellness screening test and needs careful interpretation because a positive ANA does not automatically mean autoimmune disease. But in the right clinical context, particularly when symptoms raise a genuine autoimmune question, it can be an important piece of the investigation.
However, the magic isn't in ordering more test! This is probably the part I feel most strongly about.
Good healthcare isn't about ordering every possible test.
It's about asking a good clinical question first:
What are we trying to understand?
What testing will genuinely change what we do?
What has already been tested?
What needs medical investigation?
What can we monitor?
And what don't we need to test at all?
Sometimes the answer is a specialised functional test – microbiome analysis, hormone metabolite testing or another targeted investigation. Sometimes the best next step is simply obtaining a comprehensive set of conventional pathology and really looking at it. And sometimes testing isn't the answer.
I want to see your old blood tests too! One of my favourite things is when someone arrives with years of pathology. Because suddenly we aren't looking at a photograph. It's now like watching a movie.
Maybe your ferritin has steadily fallen.
Maybe HbA1c has gradually risen.
Maybe your thyroid markers have shifted at the same time your symptoms changed.
Maybe an inflammatory marker has appeared more than once.
Or perhaps the pattern is reassuring, that's useful information too.
Your own trajectory can sometimes be just as informative as where today's result sits within a population reference range.
You are the rest of the story!
Pathology should never replace listening to the patient.
Your fatigue matters.
Your brain fog matters.
Your changing periods matter.
Your digestive symptoms matter.
Your inability to recover from exercise matters.
And equally, symptoms don't mean that there must be something abnormal hiding in the blood tests. Sometimes we need to look elsewhere.
For me, good clinical care sits somewhere in the middle.
Listen to the person.
Look at the pathology.
Compare the history.
Find the patterns.
Work out which puzzle pieces are missing.
Then build a plan that makes sense for the person.
Because a pathology result is one piece of information. YOU are the rest of the story.
Carla Wrenn
Lead Naturopath & Clinical Director
This article is intended to be informational only and represents the opinion of the author. It is not intended to be used as medical advice and does not take the place of advice from a qualified health care practitioner in a clinical setting. Please check with your healthcare practitioner before embarking upon any of the treatments discussed.
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