Thyroid test results: All tests undertaken first... - Thyroid UK

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Thyroid test results

Hypogirl50 profile image
13 Replies

All tests undertaken first thing in the morning after fasting since previous evening and not taking my thyroxine in the morning. I also as advised stopped taking B12 supplement

In November I had my blood tested by Medichecks.

TSH result came back at 19.25 mIU/L so was told to increase my thyroxine to 125mg a day

Free T 3 2.8 pmol/L which was slightly low Everything else was in range.

While abroad In January I was retested and

TSH 0.005 uIU.mL

T 3 was ok but T4 at 2.08 was high (range 0.82-1.77)

so told to decrease my thyroxine to 100 mg 3 days a week and 125 4 days

On 7th March retested and

TSH 0.01 MU/L so told to go back to 100 mg a day

T4 was normal; T3 not tested

On 24 May my last test and

I had a call from nurse practitioner to increase my dose. I asked to see my results and now realise they have got it wrong as my TSH is 0.005.

I am beginning to doubt myself with this see sawing. I am beginning to think that the Medichecks result may have been wrong?? But to have a low TSH means I am hyper so why is my doctor telling me to increase my thyroxine dosage?

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Hypogirl50
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13 Replies
Lalatoot profile image
Lalatoot

Hypo girl TSH can be very slow at reacting to change that is why you really need to go by your ft4 result and if poss an ft3 result as well.

The body does not like change and once you get into a constantly changing dose scenario as you are then things become a bit of a roller coaster. It does not make for balance or feeling well.

As you know there are 3 results in the thyroid check tsh, ft4 and ft3. I do nt know why doctors assume that TSH is always going to be right thereby allowing them to ignore the other 2. What if ft4 and ft3 are the correct results and its TSH that is out of step with them?

I would ask for your ft4 result in March and use that as a starting point for gauging how much levo to be on according to where it is on the range. Then I would stick to that dose for 12 weeks or so to give the body time to settle before doing bloods again.

Hypogirl50 profile image
Hypogirl50 in reply toLalatoot

Thanks for replying - as I said my FT4 in March was within limits(ie 24.1), the NHS do not test for T3 which is why I took two private tests previously. I followed all protocols before the tests which I had before 9.00am, 24 hours after having my last thyroxine and having stopped all B12 supplements at least two weeks before the test. So at a loss

Jaydee1507 profile image
Jaydee1507Administrator

A low TSH doesnt necessarily mean you are hyper. There are many reasons why the TSH may not be accurate and better to look at free hormone levels.

How did you do this test? Did you use the recommended protocol? When did you last take levo before this test and at what time of day was it?

Recommended blood test protocol: Test at 9am (or as close as possible), fasting, last levo dose 24hrs before the blood draw, last T3 dose 8-12 hours before blood draw & no biotin containing supplements for 3-7 days (Biotin can interfere with thyroid blood results as it is used in the testing process)? Testing like this gives consistency in your results and will show stable blood levels of hormone and highest TSH which varies throughout the day. Taking Levo/T3 just prior to blood draw can show a falsly elevated result and your GP/Endo might change your dose incorrectly as a result.

Are you always getting the same brand of Levo?

Are you taking any other meds that might affect absorption?

Do you always take your levo on an empty stomach 1 hour before food or caffeine containing drinks?

Hypogirl50 profile image
Hypogirl50 in reply toJaydee1507

As I said in reply above I followed all protocols, I have NHS prescription for Levo and on the whole the are the same brand but the 25mg differs from the 100 mg. I take it first thing in the morning on an obviously empty stomach and usually leave two hours before having anything to eat and never drink caffeine. Thanks for replying but my real worry is that the doctor is telling me to increase my thyroxine but seems wrong with the TSH results.

Jaydee1507 profile image
Jaydee1507Administrator in reply toHypogirl50

You haven't given us the actual numbers for this last test re FT4. We need your result + the reference range.

Rather than making 25mcg dose changes many prefer smaller 12.5mcg changes. You can do this by dosing every other day or using a pill cutter to cut your 25mcg tablets.

For certainty and consistency I would recommend getting the same brand at each prescription. GP can write the brand in the first line of the prescription - see image below.

named brand prescription
Hypogirl50 profile image
Hypogirl50 in reply toJaydee1507

Sorry I gave Lalatoot the Free T4 result which on both the March and May results was 24.1 which I understand is within the range of 0-25.

Jaydee1507 profile image
Jaydee1507Administrator in reply toHypogirl50

Ranges never start at 0 so could you check the range for the lab where that test was done?

Lalatoot profile image
Lalatoot in reply toHypogirl50

There isn't a range for ft4 that is 0 - 25. You might want to double check what range your lab uses.

Hypogirl50 profile image
Hypogirl50 in reply toLalatoot

Sorry I misread the results is reads 11.0 - 25.00 which still means my result is within range.

Hypogirl50 profile image
Hypogirl50 in reply toLalatoot

Sorry I misread the results is reads 11.0 - 25.00 which still means my result is within range

Jaydee1507 profile image
Jaydee1507Administrator in reply toHypogirl50

Then you really need to get FT3 tested at that dose before you start adjusting it again and continue yoyo dosing.

Hypogirl50 profile image
Hypogirl50 in reply toJaydee1507

I spoke to the doctor over the phone today (you can't see them face to face) He admitted the nurse practitioner had read the results incorrectly. However when I requested a T3 he said that whenever they ask for a T3 test it is ignored. He now suggests I take 100 mg with a couple of days on 75 mg and see after 12 weeks how I am. I would take a private test but I believe the Medichecks blood test I had was way off and really the start of this problem. FYI they had, in November 2022, my TSH at 19.25mIU/: (range 0.27-4.21 with my T3 at 2.8 pmol/l (range 3.1 - 6.8). I now believe the 19.25 was a typo but of course meant I was supposedly very hypothyroid and their report said as much and of course the doctor went by that result..

Jaydee1507 profile image
Jaydee1507Administrator in reply toHypogirl50

How have you felt at these different doses. At the end of the day that is much more important than numbers on a piece of paper.

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