Thyroid UK
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Anaemia red blood cell count

Hi there, I've recently discovered I have low folate and B12, and I am trying to decipher my blood test results as my GP hasn't labelled me as anaemic, but I'm confused about the red blood count ranges on my test results.

The red blood cell count ranges for my current practice are 3.8 - 4.8 10*12/L. My own result came back as 4.48 suggesting I'm not anaemic as I'm in the higher end of this range, therefore normal. But I have low folate and B12, iron and vit D...

So, confused, as I read that low folate and B12 suggest anaemia, which means low red blood cell count.

So, I looked up what the normal range for red blood cell count is and found it's lower than my practice's range for women.... instead of my practice's 3.8 - 4.8 10*12/L the normal range is 4.2 - 5.4 million cells per microliter (which I checked and I think means the same as 10*12/L).

Suddenly going by this "normal range" my result of 4.48 is in the lower end of the scale, not the higher end! Ok still technically "normal" but matches more the other results re my folate and vit b12...!

So am I anaemic? Seems a stupid question when my folate and B12 and iron are low. But why aren't the drs saying I'm anaemic? And why do the ranges of my practice not match the normal ranges I'm reading online? Is this like the TSH ranges that can vary and be out of touch with reality..?? Should I be concerned about a lower red blood cell count, or trust the practice ranges, and view my result as a) normal, and b) even slightly high... i just don't get it.

NB I have all the symptoms of anaemia....

16 Replies


You can have low folate, low B12, low iron, and low vitD without having folate anaemia, B12 anaemia or iron anaemia.

There are no 'normal' ranges. You need to use the ranges the lab which analysed your results uses. Different analysis machines and techniques used by different labs affect the ranges labs use. You can't compare your results with ranges used by other labs.


Thank you for your reply Clutter. I'm confused still though, does this mean that you could get one reading from one lab that is different from another lab?

With TSH levels as an example, I've read how the drs ranges vary, so I thought ranges were just the way of analysing the result?

Sorry if this is a dumb question



Entirely likely that you will get different results from different labs. It's not a problem if you use the same lab for your results. If you use two different labs which use very different ranges you would have to calculate what percentage of range your results are at to compare them.

TSH 1.7 (0.27 - 5.00) is euthyroid (normal).

TSH 1.7 (0.35 - 5.50) is also euthyroid.

TSH 1.7 (0.1 - 1.8) is almost top of range and indicates thyroid is struggling.


I think it's this article then that is still confusing me



The article indicates low, normal and high TSH. What's confusing you?


So the article mentions TSH levels, e.g. "High

TSH is >2". So does >2 need a range?



No. The opinion of the author is that TSH 2 is high. If you want an interpretation of how high TSH 2 is you would have to provide a range.


Back in 2014 I had a needle stuck in my arm, and from that single needle puncture two test tubes were filled.

One test tube was analysed by Spire, the other was analysed by Genova.

The two lots of tests had two tests in common - both companies were testing my TSH and my Free T4.

The results were :

TSH - units were mu/L

Genova 3.8 (0.4 - 4.00) This was 94% of the way through the reference range.

Spire 4 (0.27 - 4.2) This was 95% of the way through the reference range.

Free T4 - units were pmol/L

Genova 12.5 (10 - 22) This was 21% of the way through the reference range.

Spire 14.21 (12 - 22) This was 22% of the way through the reference range.

In the two TSH tests the reference ranges were different, as were the results. But when the percentage through the reference range was calculated they were within 1% of each other.

The same comments apply to the two Free T4 tests. I was impressed by how well the two lots of tests agreed with each other.

So despite the difference in reference ranges and the difference in results, it is still possible to compare results where the reference ranges are different.

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Ahhh thank you humanbean these comparisons make a lot of sense! I'd seen everyone saying the ranges were important to state, and now I see why. Thank you Clutter too. I thought ranges were just about the drs opinions of what is normal and what isn't lol.

But I'm still confused about the thyroid UK article I just posted as it mentions about cut-off points and levels. So should these have a range?



It's known that TSH <0.1 is low, 0.1 - 2.0 is euthyroid, and >2.0 means thyroid is struggling to produce hormone so may be hypothyroid. Ranges aren't required for that. In reality NHS will NOT diagnose hypothyroidism until TSH is over range whether that is >4.2, >5.0 - 6.0, and in some cases >10.0.


So is a range not required because the difference between one lab and another isn't that much? Like in humanbean's example of TSH?

Sorry, just trying to understand it.



Why is it necessary to see a range to understand an article which says TSH 2.0 is high?


I was just trying to understand the difference between ranges, where they are important and if they aren't given then that confused me because we'd just established that ranges were important. Feel like I'm chasing my tail, sorry. But thank you for helping me understand why ranges are important as I hadn't grasped that before xx


Imagine you had a test for something called X.

Imagine your result was X = 8

Nobody can tell you whether or not your level is good, bad, optimal or whatever, because without a range it means almost nothing.

If the range is 10 - 30 then your result is below range.

If the range is 8 - 20 then your result is bottom of the range.

If the range is 4 - 12 then your result is mid-range

and so on...

It is only when we have a range that we can put your result in context and say whether it is good, really bad, too high or whatever.

The other relevant factor is whereabouts in the range is optimal.

For ferritin the optimal level is mid-range or a little bit over. Top of the range or over is NOT good.

For B12 the optimal level is near the top of the range or higher. Being over the range is not a problem.

Hope this helps.

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Yes it does, thanks


Hi Clutter, just wanted to say sorry I got in a tailspin yesterday. I was anxious about my appointment coming up with Dr Peatfield and I couldn't think clearly at all. You helped me understand about ranges where I didn't before bless you xx

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