Hi
I had blood tests 3 weeks ago which show an overactive thyroid. I started carbimazole 30mg daily and propranolol 20mg daily. I am due to be having surgery in 2 weeks to remove the right side of my thyroid. However, today I have been informed my FT4 has jumped to 28.2 and TSH is undetectable. Carbimazole has now been increased to 40mg. Is this concerning? Thank you
Hello Halina and welcome to the forum :
Do you have there your actual blood test results and ranges - as if you care to share - we can better understand what is going on :
What symptoms are you dealing with ?
Was this hemi-thyroidectomy already decided on for another reason or as a result of these presumed overactive thyroid readings ?
Carbimazole is an Anti Thyroid drug and generally prescribed when there is a diagnosis of Graves Disease - so do you know you have Graves and know you have positive and over range TSH Thyroid Receptor antibodies ?
We need more information to try and help you better :
Hi
Sorry I am new to thyroid issues. I have a goitre and following a scan, was told that the goitre is pressing on my trachea. I did attend A&E for breathlessness and palpitations so was referred urgently to ENT and an endocrinologist. I had previously had no treatment for the goitre, but in the last year it has increased in size. We are trying to get my FT4 levels lowered but instead they are increasing so don’t know if surgery will be able to go ahead. My TSH is undetectable at less than 0.01 and FT4 has risen from 22 to 28 in a week. I don’t have any other results. I have been told I could have Graves but waiting for more results. Is an undetectable TSH dangerous? Why are my levels rising so quickly even though I’m taking Carbimazole? Thank you
An undetectable TSH is not dangerous in itself. (Some doctors are concerned that long-term undetectable TSH is an issue, but not in the short-term, like weeks or months. And it is subject to much disagreement.)
However, high, or very high, FT4 can be dangerous. Your undetectable TSH is indicating raised thyroid hormones. Which you obviously know!
I replied at length on a recent post:
Can I split my Carbimazole dosing?
healthunlocked.com/thyroidu...
Are you splitting your Carbimazole?
I'll not be at all surprised if this wasn't even mentioned to you.
While Graves' disease has been mentioned, have they considered an autonomous nodule? Where a nodule produces thyroid hormone entirely on its own and is unaffected by TSH?
And have they not tested FT3? Despite widespread unwillingness to do FT3 tests, they seem usually to do them in hyperthyroidism, especially when the FT4 is high.
An FT4 of 28 is high. Yes, you need treatment. But we have seen members with levels of 40, 60 and higher. Just trying to place the severity into some sort of "scale"!
Thank you, I will ask the consultant about a possible autonomous nodule on the 11th June as have telephone consultation on that day. I don’t have FT3 results, but I believe they were tested as I was told surgery could not go ahead until they were in a normal range, but wasn’t told the result and didn’t know enough at the time to ask. Thank you for the reassurance of the FT4 levels.
What level must the FT4 levels be, before surgery can go ahead please?
Each surgeon and anaesthetist will assess the individual patient. (At least, they should!) And there might be reason to allow some variation in target FT4 and FT3 results for surgery. E.g. age and prior health and anaesthetic issues.
I think they are the only ones you can ask and expect to get a useful answer, I'm afraid. (I'm sure I could find some sort of a paper, somewhere, which had numbers. But it wouldn't do you any favours if those involved with your care have a different opinion.)
OK - no worries - so you have a goitre which is now pressing on your windpipe and needs to be removed and you have a surgery date in mid-June 2024 :
Added to that your T4 level is now rising and with a TSH 0.01 the thinking being you may have Graves Disease.
Graves Disease is an Auto Immune disease that tends to only get diagnosed when your immune system starts attacking your thyroid and / or eyes - rather than defending them
Graves is a poorly understood AI disease though common triggers tend to be stress and anxiety - which I should imagine is something you are currently dealing with.
The treatment for Graves is with an AT drug such as Carbimazole and all this does is semi-block your thyroid hormones T3 and T4 rising higher and higher and slowly your T3 and T4 will fall back down into range and hopefully these additional symptoms you are dealing with, relieved.
So it would seem that the initial dose of Carbimazole was not high enough as it didn't block enough of your own new daily thyroid hormone production and why your T4 increased - rather than decreased.
There is no cure for Graves Disease - if that's what is going on - it is an Auto Immune disease - and all the AT drug drug does is ' buy you time ' while we wait for your immune system response to calm down.
As your T4 levels start to reduce back down into the range - the AT drug will be adjusted down - so the AT drug acts a bit like a brake on your new daily own thyroid hormone production - and ideally you need to keep your T4 in the range at around midway - as if the T4 drops too low you risk feeling the equally disabling symptoms of hypothyroid.
Try and relax and be selfish with your 'self ' - you are not well - and if you find you can't tolerate this AT drug - there is an alternative Propylthiouracil - PTU - for short.
An undetectable TSH is common with Graves Disease as the Graves antibodies TRab or TSH Receptor antibodies tend to ' sit on TSH receptor sites ' driving down the TSH - which in turn drives up thyroid hormone production which results in over range T3 and T4 blood test results.
Graves is said to be life threatening if not medicated with an AT drug -
but you are medicated and generally the NHS allocates a treatment window of around 15-18 months with either Carbimazole or PTU - while we wait for your immune system to calm back down again.
You might like to read the latest research if you do have Graves :-
pubmed.ncbi.nlm.nih.gov/338...
ncbi.nlm.nih.gov/pubmed/306...
Hope that helps a bit :
Sorry - I made a mistake above and have retyped and now amended the last link above - which should read - QOL post RAI thyroid ablation :
Hidden
With Graves it’s very common for levels to suddenly become very high as it is an autoimmune condition where the immune system stimulates the thyroid. A nodule or group of multi-nodules is another reason to become hyperthyroid. I’m wondering as surgery was planned to remove 1 half or lobe of your thyroid, whether that side contains a nodule causing the swelling.
Graves is confirmed by positive TRab or TSI antibodies.
Usually with Graves antithyroid is continued for months / years as remission is possible. Surgery isn’t considered until much later, but by the sounds of is your have a swelling causing physical issues & surgery is necessary due to that aspect.
The doctor has increased your carbimazole to lower the FT4 & FT3 levels as quickly as possible, but it can take a little time because it reduces production of new hormone not what already in your system. Your TSH might take longer to respond, but the TSH isn’t a thyroid hormone, it’s a pituitary hormone. The TSH signals to thyroid. My TSH stayed suppressed even though carbimazole brought my thyroid levels into range.
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