Do private testing firms use different protocol... - Thyroid UK

Thyroid UK

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Do private testing firms use different protocols to NHS? Notable variance in results twice now.


Both my Mum and I have autoimmune thyroid problems diagnosed. My sister has also increasingly been showing the symptoms. (Describes herself as "sleeping her life away", been told she has fibromyalgia. She also has terrible brain fog - often forgets what she is saying halfway though a sentence......and the rest!) Twice now we have had her thyroid function tested with the private firms, Blue Horizon first time and within the last couple of weeks Medichecks. On both occasions the private results suggested there was an issue. Within days of receiving them and taking them to the GP my sister has had a repeat test on the NHS and the results have come back significantly lower. You can see the recent Medichecks results in the image. The NHS test she had done a few days later came back with the following:

TSH: 4.22mu/L (0.3-5.6) NO FURTHER ACTION

Thyroid Peroxidase Antibodies: 106.8iu/mL (0.0-60.0). Abnormal. NO FURTHER ACTION

GP wouldn't test anything else.

I fully appreciate that our thyroid hormone levels/antibodies fluctuate, but this has happened twice now when tests have been repeated about a week apart and just wondering about this.

....dashing off to work now so will be offline for a sister has a telephone consult with the GP later this afternoon and I was just interested if any light could be shed on this in the meantime.

Many thanks in anticipation.

20 Replies

Most private testing firms use the same laboratories as the NHS, they don't do their own tests.

It's not just that hormones/antibodies fluctuate from week to week, it's also that they TSH fluctuates throughout the day. So, a test done at 8 am will be a lot higher than one done at 5 pm. TSH also drops after eating. So, given that your doctor will only test TSH, if the two tests weren't done under the same circumstances, you can't really compare them on any level, can you.

MacG in reply to greygoose

Hi Greygoose..... lunchbreak, so back online! Many thanks for responding. Should have said that I had given my sister the heads-up on having all tests done at the same time, first thing in the morning, which she did. Didn't know, however, that the TSH drops after eating. Wonder if that is why when I was undiagnosed (Hashimoto's) I had days when I just felt jittery and hungry all day despite an excellent diet and never missing a meal. There were days when I just wanted to eat and eat and after I had eaten the jitteriness and headache were briefly "soothed" but then back to square one an hour later.

greygoose in reply to MacG

No, I don't think that's the reason, because TSH doesn't make you feel anything. The TSH itself doesn't cause symptoms, whether it's high or low. :)

MacG in reply to greygoose

OK! Got that! Thanks for clarifying.x

greygoose in reply to MacG

You're welcome. :)

MacG in reply to greygoose

Update! GP has been in touch. Sister told her results are "within the normal range" and no trial of Levothyroxine. Sister persisted, and eventually told that GP would write to an endocrinologist for a second opinion......don't hold out much hope there.....

Feel so upset for her, she's in a dreadful state.

.......and so the scandal is perpetuated....

greygoose in reply to MacG

They just have no idea, I'm afraid. I'm so sorry she's upset.

What about the antibodies? Are they just ignoring them? I'm sure there's something in the NICE guidelines that talks about having antibodies and symptoms means they should treat - or was it the Dr Toft handbook? Do you have either?

MacG in reply to greygoose

Thanks for that Greygoose. Have both, will get onto it!

greygoose in reply to MacG

You're welcome. :)

Even the NHS test shows she clearly has autoimmune thyroid problem too, aka Hashimoto's. And in most countries a TSH of 4.22 would mean hypothyroidism diagnosis



There is no widespread and consistent difference between private and NHS - in many cases they are the same labs doing both. That is, many labs handle both NHS and private work using the same protocols and equipment.

There are some private labs, I think The Doctors' Laboratory (TDL) is one, which seem to only handle private testing.

We actually see exactly the same sort of difference between NHS labs.

Labs use difference analyser equipment, different testing kits, and have often gone through a process of setting their own reference ranges. These end up producing different results. Many biological tests simply are not as consistent across labs as we would very much wish. It has not seemed to be a priority to the biochemical testing industry to achieve consistency.

Differences can occur for reasons that we know about. For example, taking biotin supplements can affect at least TSH, FT4 and FT3 tests. For ordinary levels of biotin intakes, just lay off the supplements for two or three days before the blood draw. Antibodies to TSH itself cause TSH test results to be elevated. Time of day for the blood draw can make a difference with TSH being noticeably higher first thing in the morning to later on in the day. Being dehydrated affects many levels.

I'd argue that TSH of 4.22 is already too high and should merit, if nothing else, testing of FT4 and FT3. Especially with over-range TPOab.

As all UK labs - private or NHS - have to confirm to a national standard for quality control I do not believe it is at all acceptable for the GP to completely ignore private test results - which is what he is doing.

I was diagnosed, correctly I believe, with a TSH about 0.1 over range and FT4 almost exactly at bottom of range. Together with symptoms (and you clearly understand that side of things all too well) it seems clear.

MacG in reply to helvella

Many thanks for responding Helvella. I get the point now about the same labs doing both private and NHS work. Can't believe I hadn't thought that one through!! I also appreciate the point that you make about national standard for quality control and not being acceptable, therefore, for GP to ignore private test results.

I have suggested to her that her GP may be more willing to play ball if she asks for a "trial" on a starter dose of Levothyroxine as a first step in the right direction. If the GP won't agree to that at the very least, as you say, worth asking for FT4 and FT3.


She has raised antibodies and even NHS test shows high TSH. Her GP should start her on thyroid replacement.

Highly likely to have low vitamin D, folate, ferritin and/or B12 too. If GP won't test, then use private testing

If she gets nowhere with GP she needs to see thyroid specialist

Email Louise at a Thyroid UK for list of recommended thyroid specialists

When antibodies are high this is Hashimoto's, (also known as autoimmune thyroid disease). About 90% of all hypothyroidism in Uk is due to Hashimoto's (UK medics just call it autoimmune)

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

But don't be surprised that GP or endo never mention gut, gluten or low vitamins. Hashimoto's is very poorly understood

Changing to a strictly gluten free diet may help reduce symptoms.

Low stomach acid can be an issue

Lots of posts on here about how to improve with Apple cider vinegar or Betaine HCL

Other things to help heal gut lining

Bone broth



MacG in reply to SlowDragon

Many, many thanks for all of this Slowdragon and taking the time to respond. She is actually already under an endo already as, I should have perhaps said in my post, she has had Type 1 diabetes since her teens. I have said to her that her Type 1 diabetes (autoimmune) much increases the likelihood of her having autoimmune thyroid problems. This fact, however, seems lost on the medical community. She actually took her Blue Horizon results along to her endo appointment several months ago and he didn't want to know.

I think we will have to resort to private testing for the folate/ferritin etc.

Interestingly, I took a Medichecks kit along to a partner clinic (NHS hospital) yesterday as the tests I needed would have involved filling far too many finger prick vials. The blood nurse commented that they are seeing an awful lot more of these kits and knew exactly what to do etc..with it.

SlowDragonAdministrator in reply to MacG

Type one diabetes is as you say autoimmune

Susan Blum book about autoimmune recovery (sorry can’t remember title) talks about ALL with any autoimmune disease to look at gluten free diet

Yes I get my blood drawn at local private hospital- fed up with not getting enough blood on finger prick option

MacG in reply to SlowDragon

Thanks for the reference, I'll look that up.

" 106.8iu/mL (0.0-60.0). Abnormal. NO FURTHER ACTION"

??? What does it take for them to take further action? That result alone shows your sister has Hashi's. Her TSH is too high, even if (just) under the bottom of the range at 4.22, and you ignore the Medichecks result which is even higher.

Greygoose is right, time of day the test is taken is crucial. You have to repeat exactly what was done with the Medichecks test otherwise you cannot hope to compare the results.

MacG in reply to Jadzhia

Many thanks for this, yes, as I said to Greygoose she did both tests first thing under the same conditions. Like you, I find "NO FURTHER ACTION" with these results incredible. No.....make that scandalous!!

Hi MacG, Thought maybe your sister might get help if she has a private thyroid ultrasound done. I was recently diagnosed with Hashimoto's (in my family) my Thyroglobulin level is 453 I had a thyroid panel done with medichecks all other levels are normal I took it to the GP they just brushed it aside so I had a private thyroid ultrasound which showed 2 colloid cysts on my thyroid and report said Diffuse changes seen in the thyroid gland suggestive of gross thyroid disease in particular Hashimoto's thyroiditis with lymphocytic infiltration - clinical and biochemical correlation is suggested. I took this report to the doctor and got a referral to endocrine hoping and praying I get something to make me feel better, I've also found recently I have a low insulin level don't know if this is related. I was diagnosed with CFS/ME 2 years ago I wont accept this and carried on looking for other health issues. Hope your sister gets help soon.

MacG in reply to Cabernet

Thank you so much for taking the time and trouble to let me know about this. I hope you get sorted too!

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