Suppressed TSH

[Vicky789]

Just wondering why TSH would be suppressed if T3 and T4 are in range?

I currently take 125mcg levo and 18.75mcg T3

Latest results are:

TSH 0.04 (0.27-4.2)

T4 19.2 (12-22)

T3 4.61 (3.1-6.8)

I'm feeling quite good at the moment. 🙂

[SlowDragon Administrator]

Because taking almost any dose of T3 will almost always suppress TSH

Was test done early morning, ideally before 9am and last dose levothyroxine 24 hours before test

Day before test did you split T3 into 3 smaller doses spread through the day and then last 1/4 tablet approx 8-12 hours before test

When were vitamin D, folate,ferritin and B12 last tested

[Vicky789 in reply to SlowDragon]

I normally take my meds in the morning, so took the blood test before taking them. So nothing for 24hrs.I have recently had all the above tests you mention, and all were top end of normal. I take vitamin D daily as my levels drop to below range if not, so I like to keep an eye.

Thanks for your reply

😊

[SlowDragon Administrator in reply to Vicky789]

So Ft3 result is falsely low if it was 24 hours between last dose T3 and blood test

Next time you test, split as recommended

[radd]

Vicky789,

This question is frequently asked because so many GP/endos erroneously dose by TSH which may not correlate with thyroid hormone levels. Therefore, to keep TSH within range means a short fall in thyroid hormone where well-being will never be attained.

My own explanation to my GP was either a sensitive pituitary to the T3 I medicate, a basic down regulation after years of being left undiagnosed (a kind of lazy TRH/TSH secretion), or an altered base line meaning perhaps it had always been like that. Whose to know your ‘normal’ TSH levels unless childhood Central Hypothyroidism had previously been excluded.

Many of us have either an atrophied thyroid gland (thyroid antibodies) or it has been removed (thyroidectomy) or destroyed (RAI). This amount of T3 loss previously produced from the thyroid is thought to change the whole HPT axis balance as considered by many to be a key regulator. This loss is often not replaced by T4 mono-therapy and deficient T3 levels will further increase with conversion disabilities such as DIO2 impairment.

Because in a healthy body the negative feedback system used by the body’s HPT axis will determine thyroid hormone levels, the whole equation may alter with the difference in T4 & T3’s half life. There is also thought that the deiodinases enzymes that control thyroid hormone activation/deactivation behave differently with medicated T3 (combo or pure).

It has been written for a long time that T3 is a more potent suppressor of TSH than T4, but that this shouldn’t matter as the adequate T3 benefits outweigh any disadvantage of TSH loss such as less conversion. Research is proving time and again that it is not the low TSH that equates to issues such as bone loss or heart issues but elevated thyroid hormones (particularly T3).

As long as thyroid hormones are kept within range, a low TSH becomes meaningless when we medicate thyroid hormone. Your results look really good by the way.

[Star13 in reply to radd]

My own explanation to my GP was …..😳 Mine would fall off his chair if I said all that! Brilliant 👏

[Vicky789 in reply to radd]

Thanks for your time!What's HPT stand for please?

[helvella Administrator Thyroid UK in reply to Vicky789]

HPT usually means Hypothalamus-Pituitary-Thyroid - one of the classic axes of endocrinology.

You will find that and most other abbreviations and acronyms used here in my vade mecum.

helvella - Vade Mecum for Thyroid

The term vade mecum means:

1. A referential book such as a handbook or manual.

2. A useful object, constantly carried on one’s person.

Please don't get put off by the number of pages!

Nor by the fact it is targeted at people interested in thyroid issues. Much of its contents could be of use to many involved in health issues. Things like abbreviations, lists, general reference information.

In particular, it is not intended that you sit and read the document. Just that you download it and know you can look things up.

If there is anything you'd like me to add, let me know.

Not everything is in this one document - my major medicines document is still separate!

From Dropbox:

dropbox.com/s/vp5ct1cwc03bl...

From Google Drive:

drive.google.com/file/d/1ZW...

[birkie in reply to radd]

Exactly radd 👍.. My gp recently panicked at my TSH of 0.05....T3 6.6 ( I have no thyroid) immediately informing the endo who along with the gp decrease my t3🤷‍♀️ after 9 weeks I became hypo.. I did question the gp on the action of the decrease as my T3 is in range... Her reply.. "yes but your TSH is suppressed so we must decrease your meds, 🤦‍♀️.. As I'm having other problems ie... Parathyroid /calcium over range for which this very endo my gp is conversing with told me in a letter I probably have primary hyperparathyroidism, then put me over to another endo because she didn't want to deal with a parathyroid issue, is the one advising my gp what to do with my thyroid medication 😂 you can't make this 💩 up, all confidence is lost on these people, I have no faith she will do anything when I see her in August, hoping to bring my appointment forward tho.. So might not see this particular endo.. 🤞🤞🤞

[radd in reply to birkie]

Oh my goodness birkie,

I can't believe you remain untreated. Considering hyperparathyroidism was first diagnosed 2004 you are just continuing to be failed ☹️. I don't say this very often because we shouldn't have to but it is such a shame you can't receive private care.

[birkie in reply to radd]

Yeah I wish my life away everyday hoping the one scratchcard I buy I will hit enough money to go private 😢.. I honestly don't know what more the endocrinologist wants.. I've had 2 PTH of 8.1...9.5..(ranges 1.60..6.90) calciums over range 2.67..2.61.. 2.63...and still the endos won't do anything, even saying my symptoms are due to T3 meds.. Not looking at the over range PTH and calcium 🤦‍♀️ as a cause of my symptoms, I despair, I even asked a gp if he wants me to have a heart attack or stroke before anything is done... He asked me to leave the appointment 😩

[Safiktm in reply to radd]

Can I ask ,do you know if TSH levels are significantly related to pregnancy ? After years of being suppressed they are trying to raise it - is this ‘normal?’

[radd in reply to Safiktm]

Safiktm,

Yes, TSH will raise in response to pregnancy in an effort to encourage further thyroid hormone levels. Baby will depend upon Mum's supply of thyroid hormone until about 12 weeks, and Mum's own need will already be higher due to the metabolic demands that pregnancy brings & to offset the amount bound by TGB caused by the elevated oestrogen.

If you are medicating it is imperative to increase meds to ensure TSH stays low, as adequate thyroid hormone is critical for normal development of baby’s brain and nervous system. Do you have Hashimotos?

If you are undiagnosed with hypothyroidism/Hashimotos, it can be difficult to diagnose during pregnancy because of the higher levels of thyroid hormone and any autoimmunity that may reverse (for a while). hCG (human chorionic gonadotropin) also increases and stimulates thyroid hormones similar to TSH during pregnancy.

It may be better if you started a new post to attract further replies, & congratulations btw 😊

[Star13]

Many of us on this forum have suffered from Endos or GPS removing or reducing treatment due to the fact that we have a “deficient” TSH” and which ends up making us very ill if we comply. I have had years of this fight with a local NHS Endo who refused to do anything other than measure TSH and she almost killed me. Once getting myself back to some sort of health thanks to the pandemic removing her from writing my scripts, when she returned I refused point blank to follow her instructions and told her so. I was transferred to another consultant who tried the same and I repeated my complaint writing to the CEO with a formal complaint. In the meantime I asked my GP to take over prescribing which he agreed and suddenly the local CCG found the funding to support that. Funny how a formal complaint can suddenly focus their mind, especially when you accuse them of sharing data!

I requested being moved to a London Hospital Endo who Id seen privately and after 4 years of fighting I finally got a letter from him stating that In my case, due to the length of time my TSH has been low (30 years) they should not rely on TSH as a marker to treatment! I am now just about to get my first prescription from my GP for T3 who has been nothing but supportive.

And that formal complaint……one was upheld, one finally came back with a load of rubbish after a year of holding letters so I wrote back with all the facts they missed off and after four months of more holding letters I’m still waiting for the CEOs reply!

Sorry I digressed. If you feel good Don’t change anything!

[Vicky789 in reply to Star13]

I saw an endo once, despite feeling awful with a TSH of 6.5, nausea, dizziness, fatigue to the point where my 8 year old would say "I'd like to do XYZ, but you're probably too tired " she wanted me to reduce levo (was on levo only) and said I wouldn't feel hypo unless my TSH was above 10.Never bothered with them after that!

[kaylee4848]

My TSH tests came back normal for over 12 years despite silly doc not bothering to do more thyroid tests which I did not even know existed, he said boy you have all the symptoms of thyroid diseased but your tsh levels are fine. Well finally changed docs and he actually felt my throat 7 nodules, enlarged thyroid and small goiter later - I had thyroid disease and was hypo. Off to see Endo who says your bloodwork is still odd, sent me for MRI and I had a pituitary tumor - which causes tsh to come back normal on tsh tests. Now because I am on medication my tsh is totally supressed as in 0.001 and has been even lower but they keep reducing my thyroid meds - to say I feel like crap is the understate of the century.

[Vicky789 in reply to kaylee4848]

Wow, someone examined you with their eyes and hands? What a novel concept

[kaylee4848 in reply to Vicky789]

haha I know and back in the 1990's there was gasp no google, no way to look up anything really - so I just did what he said and kept dieting more and more, told him I ate a ton of salad as i love it, he patted me on the back and said be careful what you put on it - VEGGIES that is what I put on it and my own homemade dressing of vinaigrette, no creamy fatting dressings except the little oil in there. I am lucky I lived thru this doc as we now know he contributed to both of my parents deaths. He treated my mother for chronic bronchitis - she had LUNG cancer and by the time it was discovered it was too late, she died 8 weeks later. My dad had a series of heart attacks, sitting on the doctor's table his heart was fine, but he should have sent my dad for a stress test, he died 10 months after my mother - the heart doc said his arteries were totally clogged, that he must have been having pain quite a bit - but my dad just ignored all kinds of pain. So this doc killed him as well.

[kaylee4848]

Because I have a pituitary tumor, it will suppress tsh when you are on medication. Before medication, it showed my tsh in normal range but that doc never did the other thyroid tests, nor did he ever touch my throat, if he had he would have found 7 modules etc.

[pgoetz]

Hi Vicky,

I’ve been having same issue for a while. I’m in the US, and most doctors here are slaves to TSH.

Most important is how you feel!

Rarely mentioned by anyone is the half life of TSH and its pulsatile nature, which can cause TSH to fluctuate quite a lot quickly.

Here’s an answer at a blog a few years ago by an MD (College of American Pathologists):

“One of the chief sources of biological variation in the measurement of TSH (and some of the other pituitary hormones) is the pulsatile pattern of secretion and fairly short half-lives of approximately one to two hours.

“In this study TSH was released in approximately 18 pulses over the course of a day, and the TSH half-life was approximately 60 to 90 minutes. The measured TSH concentration then depends, in part, on how much time has passed since the last TSH pulse when the patient was sampled. The half-life of TSH may also vary between individuals, depending upon interindividual differences in the degree of sialylation and sulfation of TSH (for example, variation in oligosaccharide structure).”

If you want the whole reply (along with the actul Q let me know.