Different results from private and NHS - Thyroid UK

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Different results from private and NHS


Hi. Had a general set of blood tests done using Medichecks. TSH came back as 7.52. Saw my GP who tested me in the surgery and TSH came back as 2.5. These tests were both done in the space of 2 weeks. I have all the symptoms of being hypo but because of the latest test my GP won't treat me. Has anyone else had conflicting results like this?

25 Replies

These are the actual results from Medichecks. I don't have my NHS results in full as it was discussed over the phone this morning


FREE THYROXINE *11.81 pmol/L 12.00 -22.00

VITAMIN B12 154.4 pmol/L 140.00 -724.00

FOLATE (SERUM) 4.02 ug/L 3.89 -26.80

25 OH VITAMIN D *25.41 nmol/L 50.00 -200.00

Greenwall in reply to DJ_1996

It maybe that NHS has used a different reference range, so you need to ask for NHS printout in order to compare.

Treepie in reply to DJ_1996

Looks like your B12,D3 and folate are too low .

I find it hard to believe that your doctor's surgery keeps a lab in the basement so how did the doctor manage to do a test there and then? Or do you mean the blood was taken by the GP and sent off and the result came later?

What were the conditions of the two tests?

1) What time of day?

2) When had you eaten in relation to getting blood taken? Were you fasting?

3) Do you take thyroid hormones? Although it is unlikely to have had a big impact on TSH (it doesn't change that quickly), having taken thyroid hormones close to the blood test may have reduced TSH a tiny bit.

4) What were the reference ranges for the two tests? Were they different?

DJ_1996 in reply to humanbean

Sorry - I wasn't very clear in my post. I had the bloods taken at the drs on Wed at 10 am. Medichecks done at 7.30 am 10 days earlier. Hadn't eaten for 8 hours for both- although I did have milk in coffee before my Medichecks one? Could that affect results? I don't take any thyroid medication. I'll nip into my drs next week to get a printout of my results from my tests this week so I can compare reference ranges. Thanks for you help everyone - this is all new territory for me!

greygoose in reply to DJ_1996

Did you not have the FT3 tested? That's the most important number. And, as your FT4 is under-range, your FT3 could be very low, which would cause your symptoms.

I think the difference in the times they were done could very well account for the difference in the TSH results.

DJ_1996 in reply to greygoose

Thanks, that's useful to know re: times of tests. No, I didn't have FT3 tested but the more I've read around the subject since I got my results, I can see that I need this testing.

greygoose in reply to DJ_1996

The way to get the highest TSH is early morning blood draw, after fasting over-night. :)


How weird! There would be a difference but surely not by that much. NHS ranges usually go up to around 6.9 I think but obviously this changes from lab to lab. I would ring them again and ask for the results with ranges and take a note or get a print out. Which was done first the NHS or medichecks?

DJ_1996 in reply to Hidden

Medichecks was done first. I was expecting both tests to perhaps be slightly different but not vary by this much.

Hidden in reply to DJ_1996

Yes have you started any medication since? Or have you had antibodies checked? I know with autoimmune disease/ hashi's you can fluctuate.

DJ_1996 in reply to Hidden

I haven't had antibodies checked. I don't really know much about thyroid disorders but I'm learning fast from this site! The test from Medichecks was initially one of a whole load of others (Wellwoman Ultravit) as basically I had been feeling so tired, weight piling on for no reason, memory like a sieve, cold etc. I'm 50 so assumed feeling this way was aged related but wanted to double check before going to my GP.

Hidden in reply to DJ_1996

I would try and get your antibodies checked because if these are raised then that could explain the up and down with your results. Doctors generally don't test them. Some do but it's rare and hashi's is the the most common form of hypothyroidism. It's most likely you are in the decline phase which can be fast or slow. Mine took years to decline fully x

DJ_1996 in reply to Hidden

Oh really? I'll get that done then because I definitely feel rotten! If I get tests done privately would my GP take any notice of them? She said she needed to redo my first tests after I saw her with my Medichecks results - was told they needed to do the tests themselves. Don't have a problem with seeing someone privately if I have to. I can't face years of feeling like this.

Hidden in reply to DJ_1996

Your Gp can test antibodies but i think the NHS only test one type. There are two different ones but I am not hashi's and don't know too much about it. I know that I don't have raised antibodies but my thyroid is pretty much packed in. I would let your Gp do another also but try and get her to check antibodies. Ask for a print out of the results with reference ranges. I am unsure about her taking notice of your private results. Some will and some won't it's the luck of the draw. I ended up really unlucky with a gp that refused to re test my thyroid despite it having been rock bottom a year or so earlier. It's horrible when you are in that limbo phase. I felt awful before my tsh raised at all. But my t4 was bottom of the range. I eventually had to self medicate and had practically no thyroid hormone in my system. Was so poorly.

I use blue horizon for my thyroid checks haven't used medichecks yet but also like to test certain vitamin levels they do along side the full thyroid panel also including antibodies. Hypo people can easily get deficient in particular vitamins. Hope you get it sorted. X

DJ_1996 in reply to Hidden

I'll have a look at Blue Horizon. Thank you - you have been really helpful x

Hidden in reply to DJ_1996

No problem x


There are many reasons for test results varying - sometimes very significantly - other than actual variations in the TSH, FT4 or FT3 themsleves.

One that has been mentioned here quite a few times recently is the effect of biotin supplementation. High doses of biotin are quite popular in Multiple Sclerosis. This paper (or the little you can read) is very clear that variations occurs due to biotin:


There are other things that affect results: antibodies to TSH, antibodies to T4, antibodies to T3, human-animal antibodies, heparin.

I have experienced something a little similar with TSH results, although the time between my private and NHS blood tests was not 2 weeks it was longer (1st Feb and 23rd March). My private TSH result in Feb was 5.26 and NHS TSH result in March was 2.68 but yours is a bigger difference than mine and in shorter space of time.

The funny thing is, at my appointment to show the doctor my private blood test results they weren't too concerned with the results but when I went back again a week later to discuss the NHS blood test results they wanted done they commented that my TSH is now 2.68 and that they wouldn't want my TSH to be over 4.2 (the range went up to 4.2) ... but they didn't say that when it was at 5.26.

It is a shame they don't test FT3, it would have been interesting to see how that result had changed. I've never been able to get FT3 tested through the NHS, even when the GP wrote FT3 on the blood test form it's the lab who wouldn't test it.

DJ_1996 in reply to Jann207

It's frustrating isn't it. I paid for the tests originally as I felt so terrible I though I was maybe anaemic but got a test for everything just to be sure. I've bought high dose vitamin D and B12 from Amazon now and hopefully that will help. All I want to do at the minute is sleep :-(

I had BH tests done and showed a TSH of 29! Yes 29.....GP took huge offence and disbelieved - had NHS test and it showed 10... still way over but - who was correct? Exactly the same pre test conditions ( morning, pre dose) so why I don't know ( ref range virtually the same )

That's a massive difference! My GP tested my liver function as well as that was slightly high on the Medichecks test and it came back slightly high on the NHS test too. In fact they were practically identical. No idea why the thyroid result was so different. At least I'm not the only one this has happened to then. Am sure it must happen the other way too - NHS results coming back with higher TSH than private tests?

Olliphant in reply to DJ_1996

*First post here. I’m on 100mcg levo and TSH is 4... keeps rising and GP just increases the levo a bit every time. But still feel awful. T4 is 11 so under range. My liver has been tested 4 time’s in last 3 years by different GP’s and results are slightly high all the time. But they just say ‘we’ll monitor that’, don’t know why that is high’ . I think there is a link!

I wanted to do a medichecks ultra vit and deliberately did it on the same day as my nhs test as i wanted to compare tests. I had my nhs done at 08:30, fasting test and before any supplements or meds - I came home and did medichecks within the hour

NHS TSH 0.05 (0.3-4.2). FT4 23.3 (12-22)

MC TSH 0.051 (0.3-4.2). FT4 21.85 (12-22)

FT3 4.8 (3.1-6.8)

As greygoose said the all important FT3 wasnt done by NHS, I am lucky my GP is great and was willing to accept the medickecks results and not drop my levo dose. My medichecks vitamin results were very close to yours and she agreed to loading dose for vit d and to bump the others up a bit, she also took copy of medichecks for my file - I know a lot of GPs are not so accommodating or sensible.

Well following the great advice people on here gave me, I went back to my GP and asked to be retested. I got the earliest appointment and fasted and the results were almost identical to the original ones I had done with Medichecks! Here's a summary of the results -

21st March - Medichecks:

TSH 7.52 (0.27 - 4.20)

Free Thyroxine 11.81 (12 - 22)

29th March - NHS

TSH 2.5 (0.35 - 5.5)

No other results on printout so I assume Free Thyroxine wasn't tested

12th April - NHS

TSH 7.56 (0.35 - 5.5)

Free Thyroxine 13 (9 - 23)

GP was going to do nothing as free thyroxine was in range but I said he had to do something as I feel absolutely dreadful! I now have a trial of 3 months of 25mg levothyroxine and have been taking them every morning, an hour before eating, for the past week. Having read so much on here, I have ordered a test from Medichecks which also will test FT3, TT4 and the TGAb and TPOAb antibodies.

Am taking Vitamin D3 (10,000 IU per day) and B12 (1000 ug per day). I also have some ferrous sulphate I am taking to raise my ferritin levels.

My GP told me to come back in 3 months to be retested. Does that sound reasonable? Any advice on what I should be doing now would be much appreciated.


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