TSH declining whilst on carbimazole : hi, I was... - Thyroid UK

Thyroid UK

139,053 members163,202 posts

TSH declining whilst on carbimazole

Hylan23 profile image
13 Replies

hi,

I was diagnosed with Graves’ disease and I am currently taking 10mg carbimazole 4 days a week and 5mg 3 days a week. I have been taking for around 20 months now and whilst my T3&T4 levels have been in normal range for ages, my TSH has only recently been detectable( after about 16 months)

Anyway, once my TSH started to be detectable it was increasing quite steadily and my endo said it was really promising but my last blood test result saw a decline in my TSH again. From 0.15 to 0.12. It had been doubling before this. My endo was quite concerned there was no change in it for so long before so was really happy when it became detectable.

Has anyone else had this happen whilst on treatment?

Feeling really down about it as they discussed decreasing my dose soon if it continued to increase the way it had.

Just saw my results and have appointment on Tuesday.

Written by
Hylan23 profile image
Hylan23
To view profiles and participate in discussions please or .
Read more about...
13 Replies
PurpleNails profile image
PurpleNailsAdministrator

Welcome to forum.

What were FT4 & FT3 levels? TSH can be unreliable for many reason.

My TSH remained suppressed and never responded at all.

Was your Graves confirmed? Do you have positive TRab if TSI results?

Hylan23 profile image
Hylan23 in reply to PurpleNails

hi, yes graves confirmed with the antibody tests at the beginning. Have a long family history of it so no surprise with that.

My t3 and t4 are stable. Have been for ages. Attached a pic of results (fritt is free in Norwegian) t3 and t4 been great for ages on the meds just my stubborn tsh

Does that mean that you have to stay on meds if you TSH doesn’t increase?

Test results
PurpleNails profile image
PurpleNailsAdministrator in reply to Hylan23

Carbimazole lowers production of new thyroid hormone so it helps control the FT4 & FT3. The TSH will behave separately, it should respond by increasing to low levels but often it stays low especially after a period of hyper.

Focus in FT4 & FT3 if you well at current levels, keep dose the same.

Be guided by FT4 & FT3 as levels drop this is a sign you can lower carbimazole.

pennyannie profile image
pennyannie

Hello Hylan and welcome to the forum :

Can you please share with forum members your initial blood test results at diagnosis and the results of the positive antibody readings -

generally written as a TPO - TgAB - TRab - TSI - or written fully as a TSH Thyroid Receptor antibody reading and range / number alongside any antibody reading you have there.

Graves is an Auto Immune for which there is no cure - and something has triggered your immune system to turn and attack your body rather than defend it - as is normal.

There can be a genetic predisposition with maybe someone in your family a generation away from you a thyroid health issue - Graves can also occur after a sudden shock - such as a car accident or unexpected death of a loved one or seemingly occur simply ' out of the blue ' -

and Graves is considered life threatening if not medicated as for some people the T3 and T4 keep rising higher and higher causing extreme pressure on the heart and the symptoms experienced can be like being on a roller coaster - but without any of the fun.

The treatment is with an Anti Thyroid drug - and all this does is semi-block your new daily own thyroid hormone production and ' buys you time ' while we wait or your immune system to calm back down again and hopefully your thyroid reset itself without the need for any drugs.

This AI disease tends to only get diagnosed when the thyroid and or eyes are targeted by the immune system because these are major glands and organs that we rely on daily to allow us to function.

Hopefully the symptoms tolerated are relieved by the AT drug and at regular 6 - 8 week follow ups - as the T3 and T4 start to fall back down into range the AT drug titrated down as otherwise you risk your T3 and T4 falling too far through the ranges and experiencing the equally disabling symptoms of hypothyroidism.

When metabolism runs too fast as in hyperthyroid - or too slow as in hypothyroid - the body struggles to extract key nutrients through food - no matter how well and clean you eat - and non optimal levels of ferritin, folate, B12 and vitamin D will further compound your ill health unnecessarily.

Your TSH is pretty much under the control of your immune system as its the antibodies sitting on the TSH receptor sites causing the TSH to be down where it is - and guessing it was much lower at diagnosis.

and as this first phase of Graves progresses - your TSH may move, or be very slow to move, or not move at all - but what is more important is how you feel and where in the ranges your Free T3 and Free T4 sit for you to be well - while we wait :

We do now have some research that you might like to keep for future endo appointments :-

pubmed.ncbi.nlm.nih.gov/338...

ncbi.nlm.nih.gov/pubmed/306...

All things Graves Disease and AI - elaine-moore.com

Hylan23 profile image
Hylan23 in reply to pennyannie

Hi, it’s a while ago now but my initial Trab was 11 and I think TPO was over 400. Something was over 400 in antibodies anyway. I don’t have access to my earlier results.

Anyway, after this appointment my endo actually told me it had gone down from 0.20 to 0.12 so has increased my dose to 10mg a day for the next 2 weeks. She seemed a bit worried if I’m honest.

pennyannie profile image
pennyannie in reply to Hylan23

Can you please explain further -

What has gone down from 0.20 to 0.12 and required your dose of Carbimazole to be increased to 10 mcg for just 2 weeks ?

Do you mean your TSH - I shouldn't worry about that -

increasing the AT drug will lower further your T3 and T4 readings -

where are your T3 and T4 levels now -

and are you seeing this endo again then in 2 weeks time ?

This TRab and the ' TPO or something ' over 400 ' look ' high but without the full readings and ranges - means nothing.

Hylan23 profile image
Hylan23 in reply to pennyannie

Hi,

To be honest I only was asking if anyone else had their tsh go down whilst on treatment. 😊

I didn’t ask anyone for an analysis of my bloods as my endo is doing that for me.

Was more just a general question and I only replied with my antibodies because I was asked. For the record, my trab has gone down to 2.8 so that is in normal reference range now.

I just thought it was strange that after a pattern of going up every 6 weeks it had suddenly gone down and wondered if this could be normal.

pennyannie profile image
pennyannie in reply to Hylan23

It is not strange at all as at this point in time your TSH is very much under the control of your immune system :

Please address any further questions to all forum members so anyone can answer.

Hylan23 profile image
Hylan23 in reply to pennyannie

and yes the increase is for 2 weeks only, then bloods and an appointment.

helvella profile image
helvellaAdministratorThyroid UK

I'm not convinced that the small change in TSH (0.15 to 0.12) is significant.

If they ran two analyses on two blood draws taken one after then other, you might well see some variation in the results. We have seen exactly that reported when members have - rarely - had this happen.

And if not done from consecutive blood draws, all sorts of other factors could cause minor variations. Even time from blood draw to analysis!

If you want to know about your lab, you could contact the lab that did the tests and ask what difference they allow between two tests.

(Of course, that difference could be real. But small differences often end up meaning little to nothing.)

Hylan23 profile image
Hylan23 in reply to helvella

Hi, I was wrong. It actually dropped from 0.20 to 0.12 so 2 weeks of extra medication. I’m wondering if it’s from Covid I suspect I had a couple of weeks ago.

MerriJ profile image
MerriJ

Hello Hylan23

Don’t get down about your TSH , it was/is detectable.

I haven’t fully updated my profile recently but over a long period my TSH was undetectable- but as my T4 and T3 reduced it became detectable and increased !

Carbimazole is now a low dose every other day 2.5mg, dose changed in January 2024

However now at 6months later the TSH has dropped back to .37

I feel good , my Endo would like to see TSH higher again - but I felt over medicated previously when they were trying and successfully got it up over 1

PurpleNails profile image
PurpleNailsAdministrator

Be guided by FT4 & FT3 & adjust carbimazole by thyroid hormones only.

TSH is unreliable and varies daily, so testing a different times of day can account for variation.

You may also like...

Suppressed TSH causes decline in cognitive function

I have been taking LT4 75mcg/LT3 20mcg and the latest blood results 11/7/2017 are: Serum TSH Below...

2.5mg carbimazole but tsh going up

taking 2.5mg Carbimazole once a day (She recommended 5mg every 2 days) only, after 7 months of...

Graves and TSH levels too high on Carbimazole - help!

question to all. I have been in Carbimazole since June since been diagnosed with Graves and...

TSH Levels on Carbimazole

diagnosed with Grave's disease four years ago and has been on various doses of Carbimazole since....

Need help with Suppressed TSH whilst on T4 and T3 meds

I have been lucky to have been put on 125mcg of levo and 20mcg of Lio daily and am beginning to...