TSH does not respond quickly to changes in thyr... - Thyroid UK

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TSH does not respond quickly to changes in thyroid hormone levels

diogenes profile image
18 Replies

This paper demonstrates how TSH changes lag well behind changes in FT4/3 levels. The longer the dwell time of a particular set of FT4 and FT3 concentrations the longer the lag in TSH response. Useful to provide evidence that TSH is not a credible test if applied wrongly at the wrong time.

A Review of the Phenomenon of Hysteresis in the Hypothalamus–Pituitary–Thyroid Axis

Melvin Khee-Shing Leow


Published on 14 June 2016

Front. Endocrinol. doi: 10.3389/fendo.2016.00064

18 Replies
tattybogle profile image

thank you.


On a quick first glance looks very interesting and helpful. Documenting what we all know - that TSH is a very unreliable guide to treatment.

Thank you

klr31 profile image

I found this when I reduced my thyroxine - T4 moved but TSH remained the same despite two drops in dose. Why, oh why don't doctors and endocrinologists know this.


shaws profile image
shawsAdministrator in reply to klr31

They're very poorly trained about one of the commonest autoimmune conditions. They know no clinical symptoms, nor seem to know nothing else except to keep the TSH 'in range' instead of 1 or lower. They never check the FT4 and FT3.

tattybogle profile image

Can i ask an 'idiot' question ?

The examples used in this are called 'clinical vignette's'........ how is this different from 'case study' ?

Are they actual results from real cases or more like ideal examples .

The Autoimmune Hypo patient's TFT's seem much 'better behaved' than i'm used to seeing in real life on here !

diogenes profile image
diogenes in reply to tattybogle

In Singapore, the medics are very well educated in thyroidology matters and many others. I suppose that given the number of patients those who didn't tolerate T4 only well might not show up. The examples really are snapshots of a general reality as shown by individuals.

tattybogle profile image
tattybogle in reply to diogenes


Just to be 'awkward' , (i've never aspired to be 'normal', and don't want to start now )

I once tested the 'TSH can be slow to recover from suppression' thing on myself.

I'd had TSH of below 0.05 for 6 yrs (on Levo ) ,

I then withdrew Levo totally for 14 days and tested...... TSH came back at 7.897 !

which satisfied my curiosity as to whether my TSH still 'worked'. (as long as you kick it hard enough)

NOT recommending this experiment to anyone else..... feels awful.

in reply to tattybogle

I have experienced the opposite :)

My doctor took me off my 3 grains of NDT, 5 weeks later I am in a hospital ward feeling like dying, TSH came back at 0.009 and ft3 ft4 low! It took months for me to be able to leave my apartment

tattybogle profile image
tattybogle in reply to

confirming my current belief that TSH does not read books on what TSH is supposed to do....... and is in fact controlled by mischievous blue pixies, who's only pleasure in life is to try and make doctors pull 'confused' face.

Jazzw profile image
Jazzw in reply to

That was my experience too, Hidden . I didn’t let it go as far as 5 weeks thank goodness—think it was about 10 days!—but my TSH stayed stubbornly at 0.000 something while my FT4 and FT3 fell through the floor.

Scared me a bit—I’d been kidding myself that if there was ever a time when I couldn’t get hold of NDT I’d be able to muddle through until a GP put me on Levo. Now I’m not so sure...

shaws profile image
shawsAdministrator in reply to

You've had an awful experience due to the inability of the medical professionals to know very much about what is the purpose of thyroid hormones.

in reply to shaws

Unfortunately :( 3 years later still sick, can't find the dose that suits me and have all options available!

tattybogle profile image
tattybogle in reply to

It's time gp's learned not to mess with doses in patient's who feel well......... cos it's not just a matter of 'put it back' how it was before , even if you return to the previous dose.

Sounds like some people never get back to where they were.

I'm getting concerned this is what's happened to me too, but we'll see.

'First do no harm' ? if only that were true.

in reply to tattybogle

I am sorry to hear this happened to you too :(

I wish I didn't stop my meds back then, now I know better. I was overmedicated a bit at the time, but instead of tweaking the dose, I was told drop 1 grain, 2 grains, all grains.

I still believe it is possible to be on same on similar dose, but it takes extra time to get this to work again, to get all the cells to wake up again as they did have to shut down for business!

tattybogle profile image
tattybogle in reply to

That's why it's so important that they understand the TSH lag thing.

I think i was a smidge overmedicated too, but when the re-test TSH still hasn't risen in response they go mental and want to reduce again and again.

At the time i thought it must be wrong to need another reduction, but it's hard to totally ignore your GP telling you you'll die, and my aged Auntie on Levo did have a nasty Stroke. So after a while i did as i was told.

Wont be doing that anymore now though.

I'm afraid he's created a monster :)

in reply to tattybogle

It really is, I was also told I will die, that I will be in ICU in their hospital, having a thyroid storm😳then another GP I went to said that I should be happy I am losing weight (I believe that was from stress of it all).

Haha, yes, welcome to the club Hashimonster!

tattybogle profile image
tattybogle in reply to

I really hope i'm still alive when all this sh*t hits the fan (and i'm sure it will, eventually, now that we can all talk to each other, as well as just them)

I'm going to enjoy watching.

Musicmonkey profile image

Thank you diogenes

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