Thyroid UK
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High T4, high T3, high TSH- suggestions?!

Hi there,

I've already posted about this on thyroid groups til I'm blue in the face, but you guys here seem very friendly and knowledgeable so here goes, I hope I find someone who has suggestions/ideas!

I take 75mcg Levothyroxine daily. My T4 is on the high end (22ish). My T3 has been tested too and is on the upper end of the normal range. My TSH is always high, around 8 - 10. My vitamins and minerals are near the top end of the normal range. FBC otherwise normal.

I've had a number of tests that have very similar results (the last surgery I was at kept re-testing, presumably hoping one would come back normal, definition of stupid I know). I have been advised to raise the T4 to lower the TSH. However, I've been very unwell with this for a loooong time, so naturally, I did not. I am very thin, shaky, basically I have all the symptoms of an overactive thyroid. But if I lower the dose to 50mcg, my TSH goes even higher.

It is not a pituitary tumor as I had an MRI and apparently TSH would be seriously high for that to be the case, so i can safely rule that out.

I have always had problems with my thyroid since treatment. I became very ill at 21 with what looks like overactive looking back, then was eventually diagnosed two-three years later when my bloods finally showed an underactive thyroid/evelvated peroxidase. Presumably this pattern is the norm for the beginning of Hashimoto's.

However, soon after starting 25mcg of Levo, my TSH started raising. So within a few months I was on 100mcg. This was lowered as my T4 was about 28, and so for the last year I've been on 75mcg with the above bloods. I've had a period of about 6 months in 6 years where the bloods were 'in range'.

I've tried all sorts to get it to 'level out' such as coming off all other prescription drugs (inc contraceptive POP) and adopting a gluten free diet. However, this did not lower the antibodies nor did it sort out the bloods.

I want to lower my dose because I definitely felt better on the lower end of the range. 22 is far too high for me (I look ill, people have been talking about me to lecturers reporting that I'm "not eating properly/not sleeping/not looking after myself/possibly doing drugs", so it can't just be me imagining it/moaning and complaining like doctors think!).

So now I'm at a loss. Suggestions very welcome. Thank you in advance.

18 Replies

Hi Binny, welcome to the forum.

Might I just say that telling us that things are 'in range', 'at the top of the range' etc, is not very helpful. What we need to understand your situation are the numbers - all of them, results and ranges. Because without them, anything we say will just be guesswork.

So, I'm going to guess a little. :) Has nobody ever considered that your high TSH might be due to TSH antibodies? It's not very common, and I'm not sure doctors are aware of it - but vets are!

If this is the case, then the TSH is irrelevant. What matters is your FT3. And how you feel. There are no magic numbers, where you 'should' be. If you feel well, then that TSH is fine. We all need what we need - as much or as little - and trying to adjust your dose, to get your numbers into a certain bracket, is just pointless. You want to adjust your dose until you feel well - up or down. :)



Thyroid Manager indicates high TSH with high FT4 could be resistance to thyroid hormone (RTH) or TSHoma. I think TSHoma would show on MRI so RTH, more commonly called impaired sensitivity to thyroid hormone, may be worth investigating.

Do you feel better with lower FT4 and higher TSH?


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

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Okay thank you, I'll check that out. That said, I'm converting T4 to T3 very effectively by the looks of the bloods. I tend to feel better with a lower T4 but see reply to above post for further answer.

I have had it before when my TSH was in range, say 3, and my T4 was about 16, that was the best I've felt since thyroid disease (nothing like I used to feel but I think we all relate to that!)


Have you had your hypothalamus checked out as well as your pituitary?

The hypothalamus produces something called TRH (Thyrotropin Releasing Hormone).

Thyrotropin is another name for TSH (Thyroid Stimulating Hormone).

So, the hypothalamus releases TRH. The pituitary responds to TRH by producing TSH. The thyroid responds to TSH by producing thyroid hormones, mainly T4 but also some T3.

I believe that testing TRH was once a lot more common than it is now. But it would be worth asking for it to be tested in your case if it hasn't already been done.

One thing I do find bizarre ...

Imagine your pituitary is over-producing TSH for some reason. Your pituitary is examined with an MRI scan, perhaps a few blood tests are done. Then you are told you don't have a pituitary problem with TSH because your level would have to be much higher for there to be an issue.

But why? Why is there only a problem if levels are huge? Why can't people have a problem with levels that are just a bit too high? *Baffled*


That statement was just two statements rammed into one. I had a brain MRI and nothing unusual was picked up. I asked a separate doctor about pituitary tumour and he said it would have to be sky high to indicate a tumour. Sorry to confuse.

Thank you for explaining that. I will get that looked into again.


You're in agreement with Albert Einstein:-

Definition of Insanity "doing the same thing over and over again, but expecting different results".

Have you ever had hypothyroid symptoms or were you just diagnosed on the basis of blood tests? RTH is a possibility. You would need a referral to Addenbrooke's hospital in Cambridge to check it out. This referral would have to come from an endocrinologist, not a GP.

"I have always had problems with my thyroid since treatment." doesn't sound good! I would try for a referral to Addenbrooke's assuming you are a UK resident.


Ooh never heard of it, thanks. Well I just assumed everyone with thyroid problems, despite treatment, never feels well again. That's my experience anyway.

It's all a bit strange. I got ill in 2010 really acutely and overnight lost about 2 stone, I think I was about 5.5st at my worst. No doctor could explain it. My most disturbing symptom was this extreme disassociation which of course they put down to mental problems, but I was bemused because I felt fine mentally and it felt physical to me (Like I was on drugs or something).

I was tested for everything, inc. thyroid, and T4/TSH was always normal.

Anyway, the years rolled on, I got my physical strength and weight back, and I just got used to living at 70%. It was okay. Then one day I went for contraceptive pill. I was asked, 'last period?' and I said, 'Ohh now you've got me, about 8 months ago'. The doctor said, 'What, you're 23 and not unduly over or underweight, that's not normal'.

She was the first doctor to check my peroxidase and it was about 200. So I was put on thyroxine. To be honest, my functions started working again, BUT I soon started experiencing this 'overactive' feeling I get with medication, and my TSH was pretty much never normal again.


Doesn't look like RTH then. The best I can suggest is that you go by symptoms and fT3, fT4. Also ask the endocrinologist to try a different TSH assay as the immunoassay may be giving false results.

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Welcome to our forum and sorry to hear you are not feeling well.

Some people do not tolerate Levothyroxine (even with optimal iron//nutrients & adequate cortisol) and it may be in order to get TSH in range you require such a hefty dose of T4, your body simply can not tolerate it. Levo that is not used in the body becomes toxic and converts to RT3, which is thought to block further T4 from working. It would be interesting to see your RT3 results.

I agree with HB that a pituitary tumor should not be ruled out because a tumor can secrete varying amounts of hormone depending on how big and aggressive it is. Also depending on where it is positioned, a tumour may not be picked up on an MRI until it is quite advanced in growth. (I had an MRI to eliminate a pituitary tumour last year).

I am going with either a pituitary tumor (or TSHAb) or a hypothalamus dysfunction as your thyroid hormone levels respond to medication (and you are obviously converting if T3 is high end of range) but your TSH doesn’t respond (shut off) to a high level of thyroid hormone.. Also the fact this TSH level is variable ( you advised of an “in range period” for 6 months) could point to a tumour shutting on & off ( or variable TSHAb)..

High thyroid antibodies will not be helping things so off track a little .... I am not (for one moment) suggesting this will cure but .... are you gluten free ? /…

Most endos don't understand RT3 so probably wouldn't test it but considering the unusual way your hormones present, it may be worth considering. I had major troubles with T4 with (presumed) huge RT3, ending up with a psychotic episode.. hence the MRI. However, my troubles have been eliminated with the addition of T3 but I think yours are more complicated..

Knowing your RT3 levels will not eliminate the cause but may help find a direction.

You can email for a list of sympathetic endos/doctors that members have had positive experiences with.


Private labs testing


That's interesting to know, and yes, I will make a note to get the RT3 tested. I did try a GF diet very strictly (much to my family's annoyance!) but my antibodies did not change nor did my symptoms, particularly. Next I may try a paleo diet, just so I can say I tried! Thanks again for the information, everyone here seems very knowledgeable, far more than doctors are anyway!


My view, for what it is worth, is:

If TSH is found not to reflect the actual FT4 and FT3 levels, you must consider the possibility that the TSH test itself is wrong.

One situation is where you have antibodies to TSH itself. This results in the formation of macro-TSH (basically, a molecule of TSH attached to an antibody). This results in an inappropriately high reading for TSH on some test equipment/kits.

Another situation is where something is interfering with the TSH test. Not sure what would be the culprit in your case but, for example, taking biotin supplements can show falsely elevated FT4.

The first thing to do is to get your TSH re-tested by labs which are KNOWN to use different assays.


Going back to your post, "It is not a pituitary tumor as I had an MRI and apparently TSH would be seriously high for that to be the case, so i can safely rule that out." Unfortunately, pituitary tumors are considerably more common than most medics seem to realise. This paper is interesting for background though I am not suggesting that you have a heritable, or any, tumor:

However, a TSH secreting tumor would not necessarily appear on a pituitary MRI. Again, this seems unlikely, but does provide some interesting avenues:

And an overview of what to do when thyroid tests are inconsistent:


taking biotin supplements can show falsely elevated FT4.

That's news to me. Thanks for mentioning it. :)


Thanks, Clutter. :)

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Only in streptavidin affinity-based assays.


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There can be problems with the assays but the hyperthyroid symptoms suggest it could be more complex. It is worth asking for a better TSH assay (equibrium dialysis technique) and if this confirms elevated TSH ask to check for RTH.

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Thanks again to everyone who answred. I've made notes and will be following up with doctor this week.

I ahve also been looking through my results from 2010 (I keep a record of every test!) and it seems that althought my TSH has been high (~8) since I was lowered to 75mcg from 100mcg last August, along with T4 being just out of range (~22-24), my test when I started feeling unwell again in August showed that my T4 was too high (29) and my TSH was accordingly too low (0.01). MY TSH has also been accordingly low when I've been so high. Yet just a tad lower, but still at a T4 I feel 'overactive' on, my TSH shoots up. Very starnge. It's alsmost as if my TSH will only low on a very elevated T4, but nonetheless does react, so I have to rule out pituitary tumour...


Look up Hashitoxicosis. Sounds similar to me and that's what I had. May help may not but worth looking into.


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