Guys,
At the moment I'm taking 5mg of carbimazole once a day, I have been on this dosage since my t3 and t4 normalized, it has been 2 months but my tsh is still 0.01. My doctor said it would take sometime to tsh go to normal, but she also said if it doesn't change in another 6 weeks she will increase the dose. What you guys think about it? How long would take for my tsh to normalize, and why is not changing? My t3 and t4 changed, why not my tsh?😔
it is at least partly due to a thing called 'hysteresis'
TSH can take a long while to start to come back up if it has been supressed for while.
'a long while' can be anything from a few months to lots months...
so after a period of hyperthyroid T4/T3 levels , it is more important to adjust the dose of carbimazole by looking at the T4 and T3 levels ,rather than trusting the TSH to tell the truth about the levels of T4 /T3, because the TSH effectively gets stuck on 'low' for a bit even after the T4 and T3 have lowered again .
It's complex and not fully understood ,
Part of the explanation is that the pituitary gland (which makes TSH) can shrink a bit due to lack of use, when it's not being asked to make any TSH when T4/T3 levels are very high .... and it takes some time for it to get bigger again once it is being asked to make a bit more.
There is a theory that Hysteresis might be an evolutionary protective mechanism ... the body remembers it's T4/T3 levels went uncontrollably high , and tries to make sure it doesn't happen again straight away .. and so it turns down the sensitivity of TSH reaction.
If TSH was plentiful straight away it would immediately be asking the thyroid to make lots more T4/T3 again , and in the light of 'what just happened to it' it is supposed that the body thinks this might be a crap idea.
i read a paper about hysteresis the other day .. if i find it again 'ill add a link later.
Also , if the reason for the hyperthyroidism was Graves disease. then the antibodies that cause that (TRab ~TSH Receptor antibodies) can continue to mess with the TSH for a while. they kind of 'sit on it'.
(i think i remembered that right , but i've forgotten some of the details, hopefully someone who's brain is more awake than mine will come along to fill in the gaps )
Hysteresis:
ncbi.nlm.nih.gov/pmc/articl... A Review of the Phenomenon of Hysteresis in the Hypothalamus–Pituitary–Thyroid Axis
Melvin Khee-Shing Leow1
Thank you so much, it does make sense tho. The same happens to those taking steroids, your testicles will shrink because its not "being used"... Cheers for the link 😎
Hey there again :
The TSH is a very last thing to recover, and in some people with Graves it never does recover as we have TRab antibodies circulating in our blood and distorting the TSH reading.
You must track your progress on your Free T3 and Free T4 readings and also maintain your ferritin, folate, B12 and vitamin D levels at optimal.
When metabolism is running too fast or too slow - and your T3 either too high or too low for you - these core strength vitamin and minerals can nose dive through the ranges, which will compound your ill health even further.
Thank you, I did check my vitamin levels and they are all normal range. If some people never recover their tsh does that mean they need to be on medicine (carbimazole in my case) forever? How can I get rid of those antibodies? 😭
please add actual vitamin results and ranges
Within range/normal is not necessarily the same as optimal
It's important to track on Free T3 and Free T4 when treating any thyroid hormone health issue - I just highlighted the reason that is unique to Graves Disease.
There is no point " looking for remission " if your antibodies are still raging and these should also be run when suggesting coming off the Carbimazole.
How one can calm down one's own immune system response is very much up to the individual - there is a section within the Elaine Moore website link that I think I gave you last time around - elaine-moore.com
I'm afraid ' normal ' is an opinion and not a fact and we deal in facts on here, and many ranges are too wide to even be sensible.
P.S. Do you know how to find your Profile page which shows you all your previous posts and answers - simply press the icon saying More - top right on this page :
Conversely if you wish to read any forums members profile page and all they have ever written on this forum simply press on the icon alongside their name.
I did check my vitamin levels and they are all normal range.
There is more to looking after your vitamins and minerals than just getting then into the range. There is an optimal level for some nutrients that you should try to attain if you can by supplementation where necessary.
The example I always use to explain this is ferritin (iron stores).
Suppose you have three patients A, B, and C.
They get tested for their ferritin level.
The reference range (which can vary from lab to lab) is 15 - 150.
Results are :
A : 15 i.e. bottom of range
B : 82.5 i.e. mid-range
C : 150 i.e. top of range
Doctors would consider all these results to be "fine" or "normal" because they are all within the reference range.
But in reality, A would most likely feel the worst and B would most likely feel the best. And people really ought to aim for feeling their best.
Another factor is that getting nutrient levels to their optimal level also makes it easier to tolerate thyroid hormones, and also allows the body to convert from T4 to T3 more easily. Good conversion is unlikely to happen without good levels of iron / ferritin.
Note that when calculating what is optimal is always based on the reference range supplied by the lab that did the test. Ranges vary from lab to lab as I said earlier, but your results must always be compared to the range supplied by the lab - you can't pick and choose whichever one you like.
Optimal levels for various nutrients - opinions do differ :
For Serum Vitamin B12 :
a) Minimum is 500.
b) Somewhere in the upper half of the range .
c) Top of range.
d) 1000
perniciousanemia.org/b12/le...
For Active B12 :
a) Minimum is 70.
b) Optimal is 100+.
Folate :
a) If there is an upper level to the range then aim for upper half of the range.
b) If there is no upper level to the range then aim for double digits or 15 - 20.
Vitamin D :
100 - 150 nmol/L Or 40 - 60 ng/mL
Or
125 nmol/L or 50 ng/mL
Ferritin (Iron Stores) :
Optimal is 50% - 70% through the range.
There are different ranges for ferritin depending on gender and age.
A common reference range for women has been 13 - 150, although this may change in the near future since anything under 30 has now been declared by NICE to be deficient. For men a common range is 30 - 400.
For other nutrients :
If you have no information about optimal for other nutrients then mid-range or a little bit over should be safe enough.
The TSH takes time to recover & in some people is does become long term / permanently affected or down regulated.
Especially in those that have symptoms for a long time prior to being diagnosed. Or like me - my mildly hyper levels was missed for a very long time.
I’ve been on carbimazole for over 4 years and the TSH has been undetectable on the most part & I’ve been euthyroid or only fractionally out of range during that time.
Doctors do like the TSH to be in range and kept my FT4 & FT3 borderline low for several months, eventually allowing the FT3 to drop below range at which point I refused to increase carbimazole further - pointing out FT3 was below range.
Antibodies stimulate the thyroid outside the feedback loop. So TRab stimulating antibodies mimic TSH which causes over production. The TSH drops because of high FT4 & FT3.
Once levels are controlled by lowering thyroid production the TSH should respond to level, (the feedback mechanism is not directly affected by antibodies).
My hyper isn’t autoimmune & I have no thyroid antibodies & the down-regulation has been affected long term.
Antibodies (including non thyroid antibodies) can interfere with TSH reading but this causes a false increase.
you may feel unwell with under range / low FT4 & FT3 - especially if held at that level long term to “force” the TSH to respond. Your doctors will be happier the TSH numbers are looking better, but you have to function. So you might have to watch what doctors are doing. If too low you might have to argue your case & say you need to allow levels to stay where you are well.
So if your tsh is undetectable does that mean you will be on medicine untill it normalises? Do you have another option? Because I heard that doctors usually put patients on medicine for around 2 years as the medicine can be harmful long term...Another question is in terms of "feeling good" how much tsh levels play a part on it? I mean as long as your t3 and t4 are "normal" that is what matters the most?
I have a nodule so it’s not expected to normalise. I was told the treatment was radioactive iodine, but I am not keen.
I could push for surgery, the specialist brushed off the discussion - but I saw an ENT surgeon and he said I could have 1 side taken out - but not keen on surgery either.
The set protocol is to offer antithyroid for “around 2 years”, then doctors think definitive treatment should be offered. It’s based on the most effective progression treatment. Monitoring hyper patients is expensive, medic view hypo easier to treat by primary physician.
Why does the medication start causing harm after 2 years? Does it cause cumulative damage a 2 years it the limit. The answer is no it doesn’t - The “about 2 years” isn’t from a scientific basis. - The risk is the same when you start as years later, that could be 10 years later or probably 20 years later.
The risks do remain but it’s a low risk of complications occurring. Under 1%. Did doctors tell you risk & the the probability of them?
I had more minor complications develop, lots of investigations & they didn’t even connect it was due to carbimazole, (swollen salivary gland) had several appointments & 2 scans before was told it’s gone, no explanation, wasn’t until later I double checked the known side affects & saw it listed.
The TSH only purpose is to signal thyroid. Having a detectable level is desirable as it plays a function in conversation. I have hyper levels without carbimazole conversion has been ok.
Most say TSH has no impact at all symptoms it’s only FT4 & FT3. Some only need good FT3 and are not affected by low FT4 others need both. It’s an individual thing - normal for 1 might not be for another.
the "2 yrs " is for treating graves disease .. which hopefully goes into remission during that time ....... as the levels of TRab antibodies go down , the thyroid stops over producing T4/ T3, so carbimazole is no longer needed (TRab are what cause the thyroid to make too much T4/T3 in graves disease)
'Hot' nodules ,which Purplenails has, are thyroid nodules which 'over produce' T4/T3 independently of the thyroid . These do not go into remission .. they remain constant , so the high levels of T4/T3 remain constant .. and therefore the carbimazole needs to be continued forever..( or a thyroidectomy or RAI is needed.)
The TSH is not what 'needs to normalise'............. it is the T4/ and T3 levels that need to normalise... they are what has an effect on your body , making it go to fast when they are too high ,and too slow when they are too low .
Low TSH doesn't 'do' anything to the body ....it's just a message from the brain that asks the thyroid to make T4/T3 ,, when the TSH is '0' there is 'no message' ,
(TSH only 'does' something when there is 'some' TSH .. when there is some TSH, it asks the thyroid to make more T4/T3 , (the amount is controlled by the HPT feedback loop...the more TSH there is , the more T4/T3 the thyroid is asked to make ~ when the thyroid is making 'enough' T4/T3 , the TSH level goes back down to about 1ish )
Carbimazole ( and PTU , the other antithyroid drug) DO have a dangerous side effect .. (fortunately it's rare) ... it can affect the liver function .. and if this happens, it has to be stopped immediately and can't be used to control the thyroid's T4/T3 production any more ... however the risk of this side affect occurring does not increase the longer you are on it... the chance of it happening to a patient is no greater after 2 weeks, or 2 years, or 10 yrs .
This is the risk you have heard about ... however it is often over emphasised by endocrinologists because it is more efficient to treat relapsed (or continuous) hyperthyroidism with Radioactive Iodine Ablation and render the patient hypothyroid ~ it costs much less to treat hypothyroidism for life at the GP surgery with Levo coating £ 15 a year , than it does to monitor a patient on carbimazole at the endocrinology dept.
So it is true ~ there is a risk to carbimazole ~ but there is also a risk of being one of those hypothyroid patients (at least 15% of them) who do not do very well once on Levothyroxine ... which is all the NHS routinely offers to treat it with ... and you won't hear any endocrinologist admitting to this 'other' risk .
So their opinions on the risks of carbimazole need to be treated with caution .
This 'other' risk is why some people choose to stay on low dose carbimazole for years if it controls their T4/T3 levels well and they feel well on it ... they are worried about not ever feeling that well again if they accept a treatment which makes them permanently hpyothyroid.
Why has my TSH suddenly fallen on the same dose of liothyronine? 
Why the obsession with TSH?
Why is my TSH elevated while I don't have Hashi?
Why is my TSH rising when levothyroxine dose increased?
