Low TSH

[UKmale_hypo]

I have been titrating up my dose of Levo for some months now, having eventually convinced my endo that I have central hypothyroidism. (Thanks to those in this forum for helping me understand this and making my case).

As my Levo dose has increased my TSH has fallen, and in my most recent test the TSH is now below range, although my FT4 is still only at approx. 50% of its range. I have been told to target the top quartile of the range, and so have increased from 125mcg to 150mcg this week.

Unsurprisingly, my GP has flagged the TSH as abnormal and I received a text message for me to make an appointment to discuss this. Instead I have written to him, explaining that a low TSH, in the context of central hypothyroidism and FT4 mid-range, is nothing to worry about.

I realise that low TSH in the context of primary hypothyroidism can indicate over-medication, or it could indicate hyperthyroidism, both of which could be confirmed by testing FT4 and FT3. But with central hypothyroidism it is the TSH level that is the primary problem, and therefore the TSH is ignored in titrating the dose, and FT4 is used, targeting the top quarter of the range.

I do understand that if one plotted TSH against osteoporosis there would be a correlation, with low TSH and osteoporosis being 'linked', but they will only be linked in those people who are either overmedicated or those with hyperthyroidism. It is, after all, high levels of thyroid hormone that causes bone density loss, not low TSH in and of itself. As far as I am aware, the only thing that TSH does in the body is stimulate the thyroid.

So, I am posting on here to ask for confirmation that I am correct. I am 99% sure that I am, and frankly the mechanics of this are really quite simple.

So, to be clear, my assertion is that a low/suppressed TSH, in and of itself, does not cause any harm.

TIA

[SlowDragon Administrator]

Correct

See links I have just posted in reply to post above yours

healthunlocked.com/thyroidu...

[pennyannie]

Yes, I think you've got it -

though I'd just add that once on any form of thyroid hormone replacement medication the TSH is, and on itself, a waste of everybody's time and money..

The TSH was originally introduced as a diagnostic tool and was never intended to be used once the person was taking any form of thyroid hormone replacement.

Once on medication for hypothyroidism we should all be dosed and monitored on our Free T3 and Free T4 readings with the intention of these being high enough, hopefully within the ranges, to achieve T3/ T4 hormonal balance and the relief of symptoms.

A low/suppressed TSH seen in isolation, once diagnosed and taking any form of thyroid hormone replacement is not a reliable measure of thyroid function.

[Greybeard]

Hi, it's important that Ft3 is also monitored. TSH drives the conversion of T4 to T3 so it's likely that FT3 is low. How do you feel?

[UKmale_hypo in reply to Greybeard]

I don't feel great. In fact worse than before I started on Levo, though I have been putting that down to 'feel worse before you feel better' sort of thing, in the hope that hitting the sweet spot will see an improvement, as I have seen reported by others.

[Greybeard in reply to UKmale_hypo]

If your GP won't or can't get your FT3 tested you need to get it tested yourself. You need TSH, FT4 and FT3 tested at the same time, blood draw as early as possible. Low FT3 will make you feel more and more ill.

[Wua13262348 in reply to UKmale_hypo]

I too have blood readings for central hypothyroidism and have been awaiting an urgent?? appointment with an endocrinologist since May or June last year. My Health Board is at a standstill.

I have stated, in writing, to my G.P. surgery (never same G.P. twice if I have dealings with them) that I have Central Hypothyroidism blood readings going back over 2 years, and as such, TSH is irrelevant and needs to be ignored, as regards to diagnosis and dosing. I have no idea if my G.P. practice or the endocrinologist I am waiting to see are " buying into" the Central Hypo diagnosis or not.

I suspect neither have a clue about thyroids and how to deal with them, because of any input I have had from them so far.

The Endo I am waiting to see is not on the Thyroid Uk recommended list. I am in Scotland, and you can count on one hand those on the list in Scotland. My health board does , however, have guidelines for Primary Care re. Central Hypothyroidism which can be googled on the internet. They are, I know, because of this, aware that it exists. Must have been issued because of Covid, I presume. Their guidelines describe it as a mild or moderate illness from what I can remember! That does not bode well for the future.

My TSH has been in the normal range throughout from being ill since 1987, until my 20/3/23 blood reading. The first FT4 reading I have is not until 17/2/20, when it was 10.6 (12-22). I suspect there was one in 2014, the results of which they are with-holding.

I have been on liquid levo at a dose of 75mcg since 20/9/22.

From a TSH of 0.97, 21/11/22 and an FT4 of 18.8 (12-22) and an FT3 of 5.9 (3.1-6.8), my blood readings 20/3/23, are now TSH 0.14, FT4 is 20.3 (12-22) and FT3 has dropped to 5.2 (3.1-6.8).

The top quartile of my FT4 range (where I should aim to be), would begin at 19.5 (12-22), being 75%.

Do you know, from your dealings with your Endo, how far into the top quartile of the FT4 range your Endo is comfortable with?

I do not feel any better now that I am 83% through the range! My FT3 has dropped.

Conversion was 3.18, but is now only 3.9.

(See my replies to McPammy on GeeGee's earlier post. Lower, but still over range selenium might have lowered TSH which may lower FT3 .BUT, dosing 3ml from 125mcg liquid levo to get dose of 75mcg, looks a destinct possibility as to cause).

Have they given you any indication of what they consider FT3 should be allowed to reach in the range if you cannot get relief from symptoms? It would appear from your post that your FT3 is not being checked, and you will therefore not be able to answer this. Nor will they have an opinion on it, since you do not appear to have any blood readings for it?

I started levo 8/3/22 and still don't really feel much different. In the last few months my hairdresser has stated that my hair is suddenly in really good condition, much, much thicker, and I have less grey in my hair. Some of the grey is now ash coloured , I think. I'll take it! Not much to show for nearly a year on levo, although stuck on a dose of 25mcg from 8/3/22-21/7/22, until I bulldozed my way up.

[radd]

UKmale_hypo,

Correct.

This will make interesting reading for your doctor should he give you any grief 😬 ...... thyroidpatients.ca/2022/07/...

[SlowDragon Administrator]

Essential to test vitamin D, folate, B12 and ferritin too

Have these been tested

[tattybogle]

This :

healthunlocked.com/thyroidu.... (useful-evidence-that-tsh-between-0.04-0.4-has-no-increased-risk-to-patients-on-levothyroxine-as-long-as-ft4-and-ft3-are-in-range-. plus some other useful links on the subject of Low TSH ~ risks vs quality of life )

so since TSH 0.04 poses no increase risk for people with primary hypo on levo , then 0.07 is certainly not risky for someone with central hypo where TSH would be expected to be lower anyway.

There's another link on there to a study showing deliberately supressed TSH on levo didn't increase bone loss .

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I would suggest that now you are on something like a full dose ,you adjust by smaller amounts than 25mcg / day and give it much longer than 4-6 weeks to see the effect on symptoms .. more like adjust by "12.5mcg and give it 3 months" before deciding how you feel ... and if there have been some improvements at 3 months , then don't assume you need more at that point .. give it another couple of months to see if the improvements in symptoms will continue.

I went quite quickly up through 50 to 100 to 150mcg .... triedgoing back to 125 for about 2/3 weeks (felt undermedicated) , so stayed on 150mcg for many yrs , but with hindsight i wonder if 125 or 137.5 might have been better than 150mcg ,, but i never tried it properly 'on the way up' .. and when i t was suggested that i go back to 125mcg . i only tried it for a few weeks before deciding it wasn't enough.

With hindsight it would have been a much better idea to try the reduced dose of 125mcg , or 137.5mcg for a few months not a few weeks ... i now know that the first aprox 5 weeks after any dose change i will probably feel rubbish , but if the dose is an improvement i might start to feel a slight improvement again by about 5/6 weeks and those improvements will continue to build slowly if i just leave things alone for longer.

[Hidden]

Hi there,Interested as your initial levels are similar to mine... Have you felt much better whilst titrating up? I'm just beginning meds after persuading endo. Hoping to feel better, though first 2 weeks feeling rough... When did you start to notice symptom improvement.

I managed to write a letter to Endo to persuade tests for pituitary, which actually showed nothing wrong, so not sure of cause, but I was glad to rule out. Maybe you could try a friendly, persuasive letter?

[UKmale_hypo in reply to Hidden]

Hi -

I am feeling a bit better. I ended up over shooting and going hyper, though I didn't notice many symptoms of that. I went back from 150mcg to 125 mcg and that feels a bit better, though I've not yet been tested.

I have also been given a diagnosis of severe obstructive sleep apnoea, though I am having more tests for what might be causing that (after kicking up a fuss).