For so many women over 40, the story goes like this: you feel exhausted, foggy, flatter and heavier than you used to, you finally get bloods done, and you're told everything is "normal". You walk out with no answers and a quiet suspicion that you're supposed to just put up with it.

You're not. Your results hold far more information than "all fine", and this post shows you how to read them.

What does "normal" on a blood test actually mean?

"Normal" means your result falls inside a reference range built from a large tested population, typically covering the middle 95% of results, with men and women often lumped together. The top and bottom 2.5% are flagged; everything between gets called "normal", and different labs even use slightly different ranges (in Australia, the RCPA works to harmonise them).

And here's the bit nobody mentions: the people being tested aren't the picture of health you might expect. Reference ranges are built from a sample of people having blood tests done, and much of the time, that's people who are unwell.

So that range describes a population statistic, not your best state of health, and it doesn't account for the physiology that makes women different from men, or the hormone changes of perimenopause. We're not little men. So you can sit inside "normal" and still feel exhausted, foggy, flat and nothing like yourself.

Why do optimal ranges matter for women over 40?

Because optimal ranges ask a better question: not "are you in the statistical middle?" but "is this where a woman in perimenopause functions well?" Reading results against optimal ranges picks up imbalances earlier, while they're still reversible, instead of waiting for a result to fall off the end of a very wide range.

Thyroid is the classic example: a TSH at the higher end of "normal" can still come with real fatigue, weight gain and low mood, and it gets waved away every day in GP clinics around the country. The same happens with iron: the Medical Journal of Australia notes that women with a ferritin between 15 and 30 may still be iron deficient and "will not be detected" by standard cutoffs, and that under 70 can still indicate deficiency when there's inflammation (Zhang et al., MJA, 2024). In my clinic, a woman with symptoms and a ferritin under 50 still deserves treatment, and a search for the cause.

"Fine" is not a number. Ask for your actual results; you're allowed to.

What is functional blood chemistry analysis?

Functional blood chemistry analysis (FBCA) is reading standard blood tests the way a detective reads a room: each marker individually, against narrower ranges aligned with optimal health for women, and in relationship with the other markers. It lets us assess body systems and nutrient status from mostly standard, mostly bulk-billed tests, without racing to expensive functional testing.

The goal isn't just catching disease earlier; it's seeing the subtle shifts in your biochemistry that explain how you're feeling, so your plan can be specific to your body, your phase of life and your history. This is one of my favourite tools in The Perimenopause Naturopath clinic, because the information was there in your results all along; it just needed someone to read and interpret it properly.

Kirsty's story: "normal" bloods, real answers

Kirsty came to me exhausted and frustrated. Despite telling her doctor repeatedly about fatigue, brain fog, weight gain and low mood, classic signs of low thyroid function, her blood tests kept coming back "normal".

Something wasn't right, and she and her body knew it. Reading her results against optimal ranges for women showed her thyroid function sitting at the low end of normal, plus other contributors her standard review had skated past. We built her personalised Eat, Drink, and Do plan around what her results actually showed, not what the reference range shrugged at: her energy, mood and heavy bleeding improved, the gained weight came off, and, best of all, Kirsty learned to read her own results. She went from feeling rubbish and dismissed to knowledgeable and actively steering her own health.

How do you use optimal ranges for better health?

1. Get a copy of your results. Electronic or paper, it doesn't matter. I encourage every woman I work with to keep her own copy, so you can reference your results over time, share them with a naturopath like me, and see if there's a trend or pattern developing long before anything falls outside a range. "All fine" is not a result.
2. Compare them against optimal ranges for women over 40. This is exactly what I do in clinic with functional blood chemistry analysis: reading your results against the ranges where women actually feel well, not just the statistical middle.
3. Request the tests that complete the picture. If something feels unexplained, ask about a fuller thyroid panel (free T3 and free T4, not just TSH), iron studies including ferritin, and inflammation markers like CRP. My guide to iron deficiency in perimenopause covers what those results should look like.
4. Get a second set of eyes. If your symptoms persist despite "normal" results, work with someone who reads results against optimal ranges, like a naturopath or an integrative GP.

One important note: any result flagged outside the lab range, new or worsening symptoms, or results that don't match how you feel deserve a proper conversation with your GP. Optimal-range analysis works alongside your medical care, never instead of it.

You're allowed to want better than "fine"

If you've been told everything's normal but you know something isn't right, you don't have to accept "fine" as your finish line. Book a free Clarity Call; bring your results, and we'll look at them together.

Frequently asked questions

References

1. Zhang et al. Updating the diagnosis and management of iron deficiency in the era of routine ferritin testing of blood donors by Australian Red Cross Lifeblood. Medical Journal of Australia. 2024;221(7). mja.com.au
2. Royal College of Pathologists of Australasia. Harmonised reference intervals. rcpa.edu.au