Back in March 2023 I had an episode of being unable to walk (ataxia), double vision and numb extremities (fingers). I was admitted to hospital with a suspected stroke, subsequently ruled out with blood tests, CT and MRI scans. Instead I was diagnosed with Miller Fisher syndrome and hyperthyroidism. No treatment for MFS which resolved itself within a couple of weeks with vision returning to normal within 4 days, ataxia eventually resolving as well.
I was prescribed carbimazole for the overactive thryoid which I took for a couple of months - I also did a medichecks thryoid test. My question is, what happens if I don't take the carbimazole? I'd always suspected my thyroid to more more hypo than hyper (loss of the outer eyebrow seems to be a symptom of both hyper and hypo); I'm more prone to conspitation than diarrhoea and certainly am not losing weight.
My concern was that dampening down the thyroid would then put me into the hypo category.
The test from medichecks is attached as an image. I've just done another medichecks test and awaiting results after being without the drug for a few months to see if my body is capable of readjusting itself.
My confusion is around the low result of the TSH and the high result of the free thyroxine. Any help and suggestions much appreciated. Thank you for reading.
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PurpleWizardry
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How much carbimazole were you prescribed? Did you stop it yourself or did doctor say no longer needed?
Thyroid function levels should always be retested after starting usually every 6 weeks.
TSH isn’t reliable. Carbimazole dose needs to be adjusted according to FT4 & FT3. TSH tends to drop even if FT4 or FT3 only slightly elevated. If hyper especially for a prolonged time TSH can stay very low for long time.
Carbimazole should be used in cases of continuous over range thyroid levels. Not for low TSH or for transient hyper.
Have you any antibodies been tested to find the cause over over active thyroid.
TPOab (Thyroid Peroxidase antibodies)
TGab (Thyroglobulin antibodies)
TPO & TG tend to be elevated with both - Hashimoto’s (autoimmune thyroiditis) - can cause transient hyper, ultimately hypothyroid and Graves.
If Graves’ disease is suspected this MUST be confirmed with positive
Thanks PurpleNails that's more informative than I have had all year; I was prescribed 2 x 20mg tabs daily initially.
I had absolutely no follow up from the doctor; suffice to say I had a sore throat after the first 4/5 weeks and was left with no advice; suggesting to stop the medication but nothing more than my own personal research through a medichecks blood test. I stopped the medication, but am concerned there may be another flare up - I understand it's an autoimmune condition.
I will make an appointment with my GP and cite your answer if that's ok with you; I am frankly surprised at the lack of follow up, the onus is on me, it seems.
Thats a high starting dose, usually that sort of level is given if FT4 & FT3 levels are over 3x the normal range & it’s unusual to be necessary to remain of that level for very long.
Usually you’d expect levels to be back in range by 6 weeks & the dose should be halved.
I have hyper from a nodule my FT3 was almost 2x normal range & FT4 borderline when diagnosed, 8 weeks on 20mg (& Propranolol) moved levels to nearly hypothyroid.
My follow up was delayed because I was told by GP practice I had to wait for specialist appointment to be arrange to book in next blood tests, but the hospital team were waiting for results before booking appointment ….
Having no follow up is terrible but it get reported often. Were you not referred to an endocrinologist?
Having a sore throat when on carbimazole can be a sign it’s affecting white cells & the advice is to have a full blood count to rule out issues before continuing treatment. Terrible you weren’t warned of this & offered better care.
No thyroid antibody test included. This should also be done if thyroid function abnormal.
Medicheck offer TPO & TG with function & antibodies in an option pack & also antibodies with advance thyroid which also tests key nutrients.
Post your current results when you have them & you can then decide if testing antibodies necessary.
Doctors tend to dismissive of advice found on forums so don’t be specific. Say you were reading from sites & charities recommend by NHS website.
NHS info about carbimazole does link to HealthUnlocked (Thyroid UK forum). Endocrine Society & British Thyroid foundation (BTF). BTF produce a lot of leaflets which doctors hand out. NICE guidelines recommend BTF leaflets.
NICE guidelines can also be helpful in pushing for correct follow up. Although there is great scope for interpretation / doctors can sometimes seek to do minimal testing at maximal interval.
EG on Monitoring of antithyroid drug regimens
* Thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) should be checked every 6 weeks until the TSH is within the reference range, then TSH (with cascading to check FT4 and FT3) every 3 months until antithyroid drugs are stopped.
There is an alternative to Carbimazole - Propylthiourcil - PTU - for short - please ask to be switched to this ' older ' but equally effective treatment option.
Also ask that your ferritin, folate, B12 and vitamin D are run and post the results and ranges back on here for considered opinion as if these core strength vitamins and minerals have nose dived through the ranges - which can occur when your metabolism goes haywire - your health can be further, unnecessarily compromised.
The Carbimazole is an Anti Thyroid Drug and simply semi-blocks your new own daily thyroid hormone production while we wait for your immune system response to calm down -
rather like an aeroplane being put into a holding position waiting for a landing slot.
Slowly your over range T3 and or T4 readings will fall back down into the ranges and hopefully this is just a ' blip ' and your thyroid hormone production resets itself.
Quite why your immune system has decided to turn and attack your body is of course the 64 million$ question.
Do you know if any thyroid antibodies were run - as there are 2 Auto Immune health issues that tend to attack the thyroid and eyes - and both Hashimoto's and Graves Disease start off in a similar fashion and the only way to tell them apart is from antibodies - if any were found, in your blood at diagnosis - we are looking for TPO / TgAB antibodies being over range for Hashimoto's and for TRab or TSI antibodies being over range for Graves Disease ?
Graves is treated with an AT drug - such as Carbimazole and is considered as life threatening if not medicated as the T3 and T4 can keep rising causing pressure on the heart - longer term there can be talk of definitive treatment such as a RAI thyroid ablation or a thyroidectomy.
Hashimoto's is not treated with an AT drug as the ' hyper ' phase not as acute and transient and the T3 and T4 fall back down into range by themselves and longer term through continued AI attacks the thyroid becomes damaged and the patient becomes hypothyroid and requires thyroid hormone replacement.
Blood tests tend to run a couple of weeks behind symptoms - how long had you been off the Carbimazole when you ran this blood test ?
How do these readings compare to your blood test results at diagnosis ?
You are almost back down in the ranges and I would expect your T4 to fall to around 50% with your T3 tracking just behind the T4 - the TSH will be the slowest reading to respond and trust it starts creeping up in the range in due course.
Quite where your T3 and T4 need to sit to give you back your wellness and ' your you ' is the next question as with too low a T3 for you - you will experience symptoms of hypothyroidism just as with too high a T3 for you - you will likely start experience symptoms of hyperthyroidism.
I posted my last message too quickly, it wasn't complete; so basically I would like to know what I need to ask for test wise, I think you suggested ferritin, folate, B12 and vitamin D alongside the thyroid panel re-test, and then depending on what transpires, if I were to need continued medication, to go for the Propylthiourcil - PTU rather than carbimazole?
I am planning to contact the doc tomorrow to get this in the schedule all being well. Thanks again for all your help, sorry the last message containing the blood test results was so long winded, I didn't realise that I'd pressed send!
Thanks to PurpleNails as well for your input too. At least I can go in armed with a bit more knowledge!
Thyroid antibodies. GPs can requests TPO & TG but many say they can’t arrange TSI or TRab. Has to be ordered by specialists.
Carbimazole is always 1st option as PTU considered harsher on liver & you need to take 10x mg dose (more pills) with PTU compared to carbimazole.
If you know carbimazole causes severe side affects then switch.
Only other test to request is celiac screen. Gluten issues common with thyroid autoimmune. While on gluten diet test for allergy. Then even if negative (an intolerance won’t show up) trial strictly gluten free diet.
Many report no previous gut symptoms but great improvement going gluten free.
Thanks again; I once did one of those DNA fit tests, where I tested positive for the coeliac gene; I have been pretty much wheat free since then anyhow, with the odd wheat based snack once in a while (following a keto way of eating, now suggestions are that it may not be the ideal diet for my body after all). But worth a shot getting it tested anyway, thanks.
So. I'm not quite sure what you are asking me but confirm you need a full thyroid panel to include TSH, Free T3 , Free T4 , inflammation, a thyroid antibody test for Graves Disease - a TRab - which is a thyroid receptor antibody blood test - plus ferritin, folate, B12 and vitamin D :
It reads that Carbimazole gave you side effects and - do you have the PIL there - and suggest you are prescribed the alternative AT dug - Propylthiouracil - PTU for short.
If you heart is involved a beta blocker can be prescribed and Propranolol is usually chosen as it tends to lower the conversion of T4 into T3.
I forgot to add; yes I was referred to an endincronolist at the local hospital who ordered a thyroid scan in March, which eventually took place in Oct. I was told there were a couple of small nodules either side of the thyroid but again, totally unsure as to what that means; not serious enough I guess.... the hospital and my local GP aren't necessarily in communication (till I asked back in Nov).
Nodules are fairly common, most do no function & the remaining thyroid compensates for the non functioning area. Sometimes they can hyper function autonomously from the TSH & thyroid. I have a large nodule last measured at a little over 5cm which is hot or toxic. So causes continuous hyper without autoimmune.
Ask for a copy of scan report. Often there are details about the thyroid as a whole, appearance of nodules & even suggested follow up which doctors / admin accidentally miss.
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Stopping Carbimazole 
Viral inflammation of thyroid vs Graves - anyone got experience of becoming extremely hypo shortly after carbimazole?
Carbimazole or not
Confused symptoms v blood results
