Why your blood results can be normal and still wrong
Standard reference ranges are built on population averages, not on what is optimal for your body. Here is what that means in practice.
“A result that falls within a reference range does not mean it is right for you. It means it falls within a range derived from thousands of other people.”
Forbes Health
You go to your GP. You have bloods taken. A week later, the results come back. Everything is normal. And yet something is clearly not right. You are exhausted. Your concentration is poor. You do not feel like yourself. But the numbers say you are fine.
This is one of the most common frustrations we hear from people who come to Forbes.health. And it points to a fundamental limitation of standard blood testing: the reference range.
Reference ranges are derived from population studies. A result is flagged as abnormal only when it falls outside the range observed in a broad sample. That sample may include people of very different ages, body compositions, lifestyles and health states. It tells you where most people sit, not where you should sit.
Functional medicine takes a different view. Rather than asking whether a marker is within a population average, it asks whether it is optimal for the individual in front of us. Those are very different questions. A thyroid marker at the bottom of the reference range may be perfectly acceptable for one person and deeply problematic for another, depending on their other markers, their symptoms and their history.
At Forbes.health, we look at more than 400 biomarkers together. Individual values matter, but patterns matter more. How your cortisol interacts with your thyroid function, how your gut markers relate to your inflammatory load, how your hormonal profile shifts across different phases of testing. That picture cannot be captured in a standard panel assessed against a population average.
If you have been told your results are normal and still do not feel well, it is worth asking: normal for whom?