I have just had my latest blood results and have an endocrinologist appointment tomorrow.
The results show my FT4 at the bottom of the range and I have symptoms of hypothyroidism (fatigue especially and some weight gain 7lbs which is unusual for me as my weight tends to stay fixed at a certain weight minus or plus 1 or 2 lbs).
Should I ask for block and replace or add back therapy? My understanding is these aren’t the same.
I started treatment on Carbimazole on May 10th ‘24 and have read that I should stay on anti thyroid meds until my Graves’ disease antibodies have disappeared or I will go back to out of remission.
Any help is greatly appreciated.
Louise
These are my blood test results
FT3 wasn’t measured this time
Thyroid stimulating hormone
Normal range: 0.27 - 4.20 mIU/L
18/7/23 0.07
28/3/24 <0.01
17/4/24 <0.01
3/5/24 <0.01
10/5/24 <0.01
26/6/24 <0.01
19/8/24 0.20
16/10/24 2.17
9/12/24 3.67
Free T4
Normal range: 12.0 to 22.0
18/7/23 17
Normal range: 11.9 - 21.6 pmol/L
28/3/24 23.8
17/4/24 25.8
3/5/24 29.7
10/5/24 33.4
26/6/24 20.5
19/8/24 11.0
16/10/24 12.5
9/12/24 12.4
Free T3
Normal range:3.10 - 6.80 pmol/L
17/4/24 10.2
10/5/24 10.9
16/10/24 4.5
Written by
Catlover2145
To view profiles and participate in discussions please or .
Block & replacement involves higher level of carbimazole & completely disguises what levels might naturally be doing. B&R is option if levels very unstable or levels off balance. Your FT4:FT3 seem to have reduced proportionally.
Wouldn’t a reduction of carbimazole to allow both FT4 & FT3 levels to rise be best option?
Few UK endocrinologists will be familiar with concept of add back & avoid introducing levo for either block & replace or add back.
There’s research supporting negative / low antibodies increases likelyhood of remission, but often repeat antibody testing is not standard & drs stick with a 18 month guide. Some need longer. Sometimes level dictate the lowering / cessation of carbimazole.
I think I’m going by what I’ve read in my FB group and having looked at hypo symptoms I seem to be having a few now even though I’m not actually hypothyroid at the moment. I guess I was thinking adding thyroid would definitely stop me going hypothyroid.
I hadn’t considered just going to a lower dose. 🤪 Thank you for your help. Xx
When I was diagnosed in 2012 I was prescribed carbimazole 20 mg - I took it for a month then had more blood tests. At that point I got a letter from my endo - who I had not seen, the carb was prescribed by my GP - telling me to increase the carb to40mg which I did until my first endo appointment came up.
I had a blood tests showed the week before I saw the endo by which time i had gone from being very hyper to very hypo!
The guy I saw explained all the methods of treating Graves and then said ‘We use the ‘quick’ method in this hospital. The treatment last for a year. Not my idea of a quick method mind you. That was block and replace. So at that aooointment I was started on levothyroxine which increased every visit while I stayed on the 40mg carbimazole.
It was amazing though - exactly a year after I started the treatment my bloods were here they wanted them to be and the day after my final visit I stopped all of my thyroid meds and 🤞 I’ve been in remission ever since. There was no mention of staying on drugs until my antibodies disappeared - my antibodies were never tested by the hospital after the first time - but then my T3 was never tested at all.
I was very happy with block and replace to me it was very formulaic and took the guesswork out of treating Graves. You might not have a choice in how your hospital treats you though.
That’s really good that you’ve stayed in remission. I’m worried about coming off them to soon and being back to square one so your post is very encouraging. Xx
Your TSH has recovered well which I take this to mean that your immune system is no longer in control of your thyroid - and the Graves antibodies are no longer sitting on the TSH receptor sites - and the original cause of this phase of ill health causing you to ill and diagnosed with Graves Disease.
However a TSH over 2 is tending towards hypothyroidism - and years ago hypothyroidism would be diagnosed once the TSH rose over 3 -
and your T4 level is very low and not even 10% through the range and guess your T3 struggling - and causing you symptoms -
Are you still with palpitations and o/heating ?
What dose of Carbimazole and Propranolol are you now taking ?
Considering you also have Hashimoto's I'd be inclined to go with Block & Replace -
I read the longer one stays on the AT drug the less chance there is of a further Graves AI attack and the NHS generally suggest a treatment window of around 15-18 months with an AT drug -
so we need to try and ' sit out ' these next months aiming to have a T4 at around midpoint say 50% through its range with the T3 tracking just behind at say around 45% through its range.
So, depending what doses you are now taking of the AT drug and the beta blocker - you will likely need to add back in a dose of T4 - Levothyroxine to keep you T3/T4 around midpoint and hopefully with neither hyper nor hypo symptoms.
Very important that you get your core strength vitamins and minerals tested - we need optimal levels of ferritin, folate, B12 and vitamin D - as if these are not maintained at good strong levels in the ranges - your health will be compromised further than necessary.
I actually have a few hypothyroid symptoms including carpal tunnel although I have had that in the past but can usually pinpoint something triggering it.
Also cold extremities, back pain and still overheating and sweaty when walking athough not as bad. For context I wear a thin raincoat and t shirt otherwise I feel too hot and sweaty although this has calmed down a bit.
I am on 5mg of Carbimazole every day and the GP switched me to Bisoprolol 7.5mg which is being monitored as the atrial fibrillation had started again and I felt breathless and had to take breaks when on short walks due to it.
The GP said this medication also causes cold extremities. I’ve also had another week long cold recently which is the second one in a year and very unlike me. I usually get one every other year.
I take magnesium and vitamin D because my vitamin D levels were low.
I will ask my GP to run blood tests for other vitamins.
Im also very fatigued. More so than when I was hyperthyroid. It was my birthday this week and I have no inclination to go out and celebrate which is very unlike me even though I’m not into going out. I just feel completely wiped out.
What should I do if my doctor doesn’t want to do addback/block and replace?
Sorry, I wasn’t sure if they were the same thing. I’ve just seen both mentioned and didn’t know what the difference was or if they meant the same thing.
Ok then - so with B&R - it means we Block your own thyroid hormone production and Add in a measured dose of Thyroid hormone - so your thyroid levels T3 and T do not fall too far through the ranges -
A bit like an airline pilot putting the controls on automatic pilot - and just cruising miles up in the clouds with very little need to do much else, before getting ready to prepare for landing.
Block & replace is a high or full dose of anti thyroid to ensure any natural function is prevented & full replacement hormone dose to replenished what is required.
Titration is preferred as this allows an adjustment of antithyroid to lowest effective dose to bring thyroid levels into range.
“Add back” is a higher dose of antithyroid than the lowest effective dose but still high enough to thyroid push levels to hypothyroid levels. A reduced replacement is given. Seems to give a stabilising effect. It’s discussed by Australian patients.
Thank you PurpleNails. I still have brain fog and get very confused over the whole thyroid issue but that makes complete sense.
I’m so tired of feeling tired. I feel ready for bed right now and only woke up at 9am today although I have bad insomnia at the moment. This makes my thinking worse. ☺️
Thank you - I'm not aware of this ' add back ' treatment option -
It seems preferable to find the lowest possible dose of the AT drug so to allow as much of ones own thyroid hormone production to be released into the blood stream - reverting as close as possible to the natural workings of the body -
Having stopped the Propranolol one would hope this leads to a slightly better level of T3/T4 -
and there is room to adjust the Carbimazole down - by chopping the 5 mcg tablets in half and taking - 2.50 mcg of Carbimazole daily - and see if this allows enough thyroid hormones to be released into your blood stream to take your T4 a little higher into the range to around midpoint where you should feel more comfortable.
And this way you maybe able to get through the next few months just taking a small dose of the AT drug - maybe worth trying this first as the closest option - to coming off all medications when seeking ' remission ' -
the only issue I can see is that since you have Hashimoto's you are likely to experience erratic own thyroid production with this thyroid AI disease - the symptoms of which are very similar to those of Graves -
so possibly end up being further confused - it's a difficult place to be - but worth trying to sit out these next few months rather than consider definitive treatment.
I would tend to be led by the consultant as I think it also depends upon the skill set of the endocrinologist responsible for your treatment regime.
I have just scrolled through all my all previous thyroid results on the NHS app and at one point my T4 was well in the hypothyroidism range however it moved back in range and I wasn’t even aware (I was extremely unwell with depression at that point). However at that time I wasn’t aware of the best time to test your blood so that may be why.
I think I will go with the endo’s opinion tomorrow. Thank you for your help xx
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Any Advice on blood tests results and feeling rubbish 
Opinion on these TSH, T3 and T4 values
Totally confused
Advice need re T3 before hospital appointment 
Check up after lockdown gives me a surprise!
