This can’t be right: I want to ask others... - Thyroid UK

Thyroid UK
101,228 members115,473 posts

This can’t be right

I want to ask others something, because the immediate conclusion seems so stupid it can’t be true.

As I have understood it, and I must be wrong, local reference ranges in endocrinology are set by measurement of local populations. But, at the same time, an individual’s personal set point varies very little (in regard to thyroid hormones anyway).

So, I was born in Scotland. I don’t know what the local range is, although I could look it up, but say the range for ft4 is 12-22.

When I was 30, I moved to London. At that stage, my endocrine function was fine and had never been tested. It was only measured here after I became ill, and my ft4 was first measured at 12, declining over time to 10. Ft3 began at 4.50. Declining to 3.50. My tsh was always 0.1 or less.

Now this is the bit I don’t get- would my ft4 be low in Scotland but ‘within range’ in London (local range 9-22)?

Why?

I must have missed something, but what?

71 Replies
oldestnewest

Ginny52.

Different labs use differing ranges and your test result would be indicative of the range used. ie if it were 70% through range in one set of ranges, theoretically it should be the same in another, no matter what the ranges are.

1 like
Reply

I don’t understand that. In the made up example I gave, ft4 of 9 would be low in Scotland and normal in London. Why?

2 likes
Reply

This just seems more of the same lunacy that has this country set a threshold of tsh 10 for treating primary hypothyroidism when other countries treat at half that. Why can’t it be standardised?

4 likes
Reply

Ginny52, Your TSH (and FT4) number will change to reflect the range of the testing lab. I think of it in the same way as currency conversion. Something priced at 10 GBP will (at the current conversion rate) become 11+ Euro.

2 likes
Reply

I just don’t believe them. If these ranges, and cutoff points, and treatment/no treatment depends on something so variable and subjective, how can you have confidence in it?

Especially when the implications can wreck your life?

6 likes
Reply

I think most people here will agree with you. The current approach to diagnosis and treatment of hypothyroidism is wrecking so many people's lives.

6 likes
Reply

It’s awful!

1 like
Reply

I've been asking this since losing my thyroid 3yrs ago as it has destroyed my health.

1 like
Reply

I’m so sorry xxxx

Reply

I don’t understand either - but I live in London and I was called into the doctor the minute my TSH exceeded 4 Even though my T4 is ‘normal’ ( but low for me)

1 like
Reply

But, it wouldn't be 9 in London. It would be the same percentage through the range.

Imagine in Scotland the range was 12 - 22, and your FT4 was 17. That would be 50% through the range.

You go to London, and the range is 9 - 22, your FT4 would be 15.5, 50 % through the range - give or take a point or to.

Given that the ranges change with the machine, you FT4 wouldn't be the same result on every machine, but it would be the same percentage through the range.

7 likes
Reply

So- in Hounslow I’m 10 ie one point above the bottom of the range (9-22), but in Bristol (12-22) I’d be....13?

1 like
Reply

Possibly, yes. I'm no good at working out percentages, though. But, if the range changes, so will your result.

But, we all know that the ranges are just a joke. They're far too wide, for the most point; they have nothing to do with your personal set point or your needs; and the sample population more than likely included quite a few undiagnosed hypo and hyper people. They are pretty much unfit for purpose, and everybody knows that except the doctors that use them to suit their own agenda. The whole system needs reinventing, not just the ranges.

7 likes
Reply

I know. It just looks like such a shabby effort at obfuscation!

2 likes
Reply

Curiosity question. What types of people do they create these labs ranges from ? Sick people, sick but treated, young, elderly. How are lab ranges decided I heard from others that are sick.

Reply

That's a very good question. And I'm not sure that anyone has any definitive answer. I would imagine that they use the blood from people who go to have blood tests - which, of course, would mean they are sick people, with one sickness or another. I've never heard of them putting out a general appeal for people to come and have their blood taken for the purpose of creating ranges. But, this goes for all blood test, not just thyroid tests, so I really don't think they are very scientific at all! Which is why, for myself, I tend to pretty much ignore ranges.

1 like
Reply

Which makes the reverence with which they treat them insane!

Reply

Absolutely. No-one is denying that. But, they don't know enough about thyroid - or blood tests, come to that - to understand that.

2 likes
Reply

Not quite. But close.

The gap (the reference interval) in Hounslow is 13. The gap in Bristol is 10.

In Bristol you would be 10/13 of a point above the bottom of the range!

Not saying that to be pedantic, that is close enough to one for most of us. But you have to view both the bottom and top of the range AND how big that reference interval is.

4 likes
Reply

A fairy arbitrary looking number seems to have the potential to cause almost limitless suffering. I think I would have to have a sample sent to Bristol and showing 12.5 to believe it!

They can hide behind ‘guidelines’ when it suits them, but there is nobody to enforce guidelines that would suit the patient.

3 likes
Reply

Completely agree with you and not only this I have also been told it varies GP to GP so one GP surgery may consider a range to be “normal” that another treats for. Prime example my results! Come back to my GP “normal no further action” yet my specialist reads these and wants me to have my thyroid removed!! Like you say! Potential to ruin lives because they appear to be working on their own crazy metrics!

3 likes
Reply

That’s how I ok at it. My NHS blood tests have lab ranges that are totally different to my private ones - I just look at where I am within the ranges and it always works out that I’m around the same position for both - ie near the top, middling or scraping along the bottom.

5 likes
Reply

Hi Ginny,

It does seem complicated on the face of it but the ranges applied depend on the technique used to measure the range - labs use different standardised methods for testing and these methods result in differing ranges ie if a range is 4-14 (example not real) in one area due to the method used there and 12-22 in another area using a different method then a value of 4 in the first example would be a value of 12 in the second- I hope that’s making sense - what you can’t do is apply a level measured from one lab area to a differing range from another area as it will be meaningless due to the different methods of measurement and ranges applied to them. I hope that makes some sense and I haven’t over complicated this,

Nikki x

3 likes
Reply

The reference intervals are determined by selecting a sample population which may include different ethnic groups. Although there are differences between raves the major factor is the assay.

2 likes
Reply

That’s another thing about the ‘sample population’ idea- I was born into a probably 90% ethnic monoculture (50s Scotland). How can that relate my unknown ‘set point’ for what ft4 should be to 2020 Hounslow?

1 like
Reply

Some labs just adopt the manufacturer's lab ranges without even attempting to look at the population they are serving.

Quite obviously, mail order testing completely removes geography within the UK.

4 likes
Reply

I never thought of that! I wish I’d had a serum test done before treatment! I did have a urine test, and Dr P said f4 and 3 were unacceptably low (his words) but the units are completely different and nhs don’t seem to see it as meaningful.

1 like
Reply

Many agree that having a test when healthy would be the best starting point.

It would at least be some sort of indication of where your personal set points might lie.

7 likes
Reply

If only!

1 like
Reply

They do this with other health conditions. Men might want to have a "baseline" PSA measurement when they are young to provide a starting point. They are starting to do DEXA scans on older women to get a baseline for bone density.

Reply

Negligible compared to evolution.

1 like
Reply

Also the reference range of sample population first used would obviously include already ill people? That would skew the 'healthy' level!

1 like
Reply

Hi

If you can afford it book to see an endo privately. They will test ft4/3 & ths levels , talk to you about how you feel / symptoms etc. They look at the actual results not based on any range of levels combined with symptoms and how you feel daily . They can then write to your GP with recommended medication dosages etc. The GP can’t really ignore this as the Endo is the expert doctor for your illness. Do your research to find a really good Endo . I’m happy to give you the name of mine if you would like it.

Good luck

1 like
Reply

Private Endos are not necessarily any better than nhs ones as most work in both, the private Endos I and many others have seen have been useless and GPs can and do ignore private Endos recommendations.

5 likes
Reply

I agree a lot of them are rubbish!! Which is why I said do your research in order to find one who has a reputation you like the sound of. Mine is brilliant .

Your GP could ignore the advice from the Endo but you can challenge why . Also if something goes wrong they would be taking a huge risk ignoring expert opinion/instructions & therefore, most GP’s would go with Endo diagnosis - they may not like it or agree with it!

1 like
Reply

I researched and found my parathyroid/thyroid private expert, how wrong that turned out !! Another one I saw has a great reputation yet he insisted I didn't need Levo despite me having no thyroid 😳

2 likes
Reply

yet he insisted I didn't need Levo despite me having no thyroid 😳

WOW. Just wow!

Reply

An absolute incompetent , clearly 😵 MaisieGray had it right yesterday - the parrot 🦜 would do better

1 like
Reply

And WOW again!

2 likes
Reply

That was my experience Doris. They referred to the endo as my 'private GP' and told me to see her about the meds. Going private, even for tests can give your GP a get out clause under NHS regulations.

1 like
Reply

I wonder if a GP has a duty of care to a patient and cannot just ignore stuff simply because the Endo is private especially if the Endo is keeping the GP in the loop

1 like
Reply

I wish that were true. Sadly NHS regulkations mean that if you have a private medic, they have the duty of care. It was I suspect designed for people who have private medical insurance with the intention of protecting NHS resources from abuse by private doctors and also meant for private GPs rather than specialists.

1 like
Reply

in my own recent experience this is the obstacle that the GP has used to avoid testing my T3 levels despite a written request from the (private) Endo and the Endo completing the necessary lab test form which the GP discarded and replaced with their own form without ticking the T3 box.

Reply

Well all I can say is mine has been brilliant. Even wrote to my GP telling them which tests he wanted done on the NHS ( so I didn’t have to pay for private tests) .

Then once all the tests were done he wrote again with his diagnosis and recommended prescription.

I realise not everyone gets the same treatment, I’m just explaining my experience and suggesting it might be worth a try .

Don’t shoot the messenger !

3 likes
Reply

There are a number of issues here. Firstly, a secondary care consultant, whether private or NHS is not hierarchically "senior" to a GP, and therefore a GP is not obligated to take on board the specialist's recommendations. Whilst you might expect that in principle, a generalist would defer to a specialist in the area of their specialism expertise, it isn't a given. Health treatment is not exclusively a science, it's partly an art especially at primary care level, and there is often more than one way to manage a condition; so there isn't always agreement between Drs in any case. The other key factor is that an NHS Dr is not obligated to implement anything suggested by a private consultant and can suggest the patient returns to their private medic for continuation of that aspect of their treatment ie pay for it. So for a private consultation to be fruitful through the good offices of the NHS (pause for laughter to subside) a patient needs both a skilful private Endo and a willing and receptive NHS GP, which combination is a rarity within thyroid care in particular.

5 likes
Reply

Sorry did you read my response . I was just offering a suggestion following my own experiences. Trying to be helpful to OP and give some hope encouragement.

I never suggested anything was set in stone throughout the UK , as we all know it’s far from it.

PLEASE don’t shoot the messenger

2 likes
Reply

I'm not shooting the messenger at all, I'm replying to a public post, and positing different considerations that can affect outcomes in similar circumstances in order simply to inform awareness.

2 likes
Reply

To expand further, I have two friends who saw the same private Endocrinologist. The first was given help by the Endo, above and beyond even what might be expected, that resulted in them being prescribed NDT by their NHS GP; the other was given only minimal assistance by that Endo which resulted in no such thing occurring with their NHS GP, and that friend has had to fund her own NDT. The NHS GPs are in different practises but within the same CCG so subject to the same CCG prescribing policies etc. So if you knew only of the experience of one patient, you might have a different expectation of your own visit to that Endo, than if you knew only of the other.

1 like
Reply

I think this is a good point. Different patients for whatever reason can end up with different outcomes. I've had fairly bad experiences with two doctors from the ThyroidUK list, and even a bit of a mixed experience with the beloved Dr P. Obviously other people have had much better experiences!

1 like
Reply

I’d love the name of your endo although I don’t know when I’ll be able to afford it- I’ve been too ill to work for three years. My problem is that the gp takes the word of the nhs endo, who is just wrong, rather than the private one.

Reply

Sent you the details via PM

1 like
Reply

Doris, if you know a good one, I’d be very grateful. Maybe you have to pm me?

Reply

Lab ranges are almost irrelevant! It's your personal range which matters and you find this by trial and error linking the most consistent circumstances you can get for each blood test with your symptoms and wellbeing. If you can afford it doit privately by finger pick at the most convenient ad consistent time and stick to the same Lab where you are in the NHS geography.

1 like
Reply

They should be but unfortunately as far as I can see lab ranges are king. It doesn’t matter how poorly you are feeling if you fit somewhere within the range then that’s ok, you’re within range. That it might not be your optimal point in the range so that you actually feel well, doesn’t matter at all, you’re ‘within range’, your doctor is happy and if you don’t feel well then - tough luck. There is no such thing as fine tuning on the NHS.

I do what you recommends and do finger prick testing from the same lab all the time.

Reply

My problem is that the gp believes the nhs endo rather than the private one although the nhs one has no time for symptoms, history etc. The few points difference at the bottom of the scale is the difference between believing I have sub clinical hyper and secondary hypo- nhs won’t do tests and gp has withdrawn the leve the private endo prescribed. I’ve been so ill.

1 like
Reply

Ideally we could be all within the right place if we scrapped all the different machines and started again with identical machines with the calibration the same. But we all know that is never going to happen and yes would be a great waste of money for the NHS. I am sure we wouldn't want to put them in that situation but hospitals have increased of the years and some may even have more than one machine ( I have seen posted either here of elsewhere where the local range differed as they had two different machines so you had to make sure the ranges were given accordingly). At one time may be for testing people had to visit the nearest testing station until something more local so that would be most likely calibrated differently as well. So it's never something that will change. A personal plus point is my local hospital the top of my T3 range is 6.8 but I travel elsewhere where the top is 5.7 and they never put this with my results so my GP wasn't concerned if I got a 'high' reading though the Endo doing my testing was! So never get two telling me off!

I don't think the local variation makes much difference from what I've read.

1 like
Reply

As everyone else has said it’s not fit for purpose. It’s also postcode lottery on funding, hence why a lot of people remain untreated & failed by the system. I was failed by nhs till I collapsed & then found a brilliant private Endo who successfully treats me. Good luck👍

1 like
Reply

Can never believe how bad they are. I’m so glad you found a good one in the end- not in London by any chance?

Reply

In Surrey

1 like
Reply

This kind of explains how ranges are determined clinlabnavigator.com/refere...

But it’s “expert opinion” that determines the levels or cutoffs that become “actionable”. Our docs in the US aren’t as constrained as yours. But I’ve been reading thyroidpatients.ca/campaign... with issues more closely aligned to yours in the U.K.

As a nurse our medical director always emphasized “treat the patient, not the numbers.” And that lab results were to be used as confirmation of a diagnosis or to check results of an intervention, not as a driver. An example we see over and over is someone has a thyroidectomy, is put on levothyroxine and develops palpitations and instead of adjusting meds the patient is given beta blockers and maybe an anti-anxiolytic to treat this side effect of incorrect dosing.

I love that Greygoose and others here use “percent through range”; when looking at our thyroid level it shows how wide those ranges really are - and how irrelevant TSH is for most of us.

Patti in AZ

4 likes
Reply

I told my GP that ‘the ranges’ were so wide that to be below them at either end you would be seriously ill. I was going to say so ill that your condition couldn’t be missed but alas that’s not true.

I was well below the lower level of the range, totally falling to pieces, had been for a long time and yet a doctor I saw three months before being diagnosed with Graves’ disease thought I was ‘needing a holiday’!!! Then you read on here about people who are way over the upper limit and feeling very ill who are completely ignored. The ranges are just ridiculously wide, designed so as not to have to bother treating anyone until they are literally on their knees - one of my side effects, once I got down to that level I didn’t have the muscle strength in my thighs to get myself up without some sort of help.

Reply

Ginny52, in addition to your main question about ranges, there is also the issue of how to interpret. If you go for one blood test and your freeT3 or freeT4 is at the very bottom of the range but still inside it, that is a very low result and shows you probably need treatment. It's not much different from a result that's just under the range.

Unfortunately some doctors will treat these ranges as gospel, and see the out of range result as a problem, and inside the range as fine. It can often be even worse than this, with doctors wanting to see things not just outside the range but far outside.

Both these are a bad interpretation, I think. A healthy patient would have free hormones in the centre of the range, so anything far off that is a suspicious result.

2 likes
Reply

This is exactly my problem, and I honestly feel as if the endo found it more important to prove me wrong than to try and diagnose.

Ft3, 4.5 declining to 3.5, Range 3.5-6.5

Ft4 12 declining to 10.5 Range 9-22

Tsh 0.1 Range. 0.3-5

People here pointed out that central hypo looked more likely, but these ninnies just kept repeating like parrots

‘I explained to her that CI would be low Tsh with low t3 and t4- but it IS low, just not low enough for them. This was used to withdraw the leve prescribed by the (famous) private endo I’d seen. Since then I’ve had to buy online.

I’ve been so ill. I’m pretty sure there are other problems from hypopituitarism, and I really need help, but no, numbers rule. I want my life back!

1 like
Reply

Getting central hypothyroid diagnosed is a real minefield :( It seems like there is no clear path to prove you have it.

A forum regular was eventually able to find her own evidence, that she had very high prolactin, and eventually had an MRI to prove it to doctors. Although she still has to buy her own hormone.

I've read that 40% of pituitary tumours produce excess prolactin, so you can be either lucky and have that marker, or unlucky and not have it. I think the exact impact it has on hormones depends where the tumour is located on the pituitary.

1 like
Reply

PS: I also have an unusual form of hypothyroid which is not acknowledged and have to buy my own. I'm a lot better than I used to be, but still quite disabled. There are a lot of us on the forum :(

1 like
Reply

I haven’t got a tumour- it’s something called Sheehans Syndrome that you get from pituitary infarction from haemorrhaging during pregnancy or delivery. The most likely deficit is growth hormone, but they won’t test for it. You just have no way to prove it, especially if it was a long time ago, and you can no longer get records of blood loss etc. I just stagger on buying it on line too- but I don’t have to tell you ❤️❤️❤️❤️

Reply

Good to hear that you have more understanding of what the cause is. But that's even more of a disgrace that you can't get proper diagnostic tests and treatment :(

I was very shocked they don't treat us. I originally had thyroid cancer, and so my thyroid was removed. I really really thought that because my illness was caused by treatment there would be a path to diagnose and treat it. But they know so little, I was just sent home to get on with it being very impaired, in bed most of the time.

1 like
Reply

I know what it is entirely thanks to Thyroid Uk (humanbean) to whom I am forevever tankful or I’d believe I was mad as well! Xx

1 like
Reply

This is appalling! Grrrrrrrr!

1 like
Reply

You may also like...