Since being told my TSH was 100, I've been doing alot of research and can't find any articles that discuss TSH levels in great detail, bar what ranges they should be, and anything above 10 is overt hypothryoidism- and that's the end of the information.
Does anybody know just how high TSH levels can go?
I assume my TSH reading would be classed as severely elevated.
That's a good question. Mine was 69 at diagnosis and my then GP said he nearly fell off his chair when he saw the test results. He'd never seen one that high in his entire career.
Highest I've ever seen as a statistical analyser of tests is 150 for TSH and undetectable FT4. Any numbers like that mean imminent death from myxoedema unless something is done very quickly. The person involved was the wife of a senior serviceman who was first diagnosed with mental problems - caused of course by the lack of thyroid.
diogenes, first diagnosed with mental problems - caused of course by the lack of thyroid.
Ditto. Twenty years on and nothing seems to have changed with regard to diagnosis and treatment. Medics remain largely ignorant of the effects of thyroid hormone imbalance on the brain and are far too quick to hand out antiDs, psychiatry referrals etc.
If someone is hypothyroid, their TSH rises.
If the initial increase in TSH is insufficient, the pituitary will produce more TSH. And so on due to the feedback loops. But there must be some maximum output that an individual’s pituitary can achieve.
There is evidence that in long-term hypothyroidism, especially if severe, our pituitaries increase in size. So-called pituitary hyperplasia.
A simplistic interpretation is that as we need more TSH, so our pituitaries increase their capacity to produce TSH. And the longer we are severely hypothyroid, the more that capacity increases.
If that is anything like reality, we would expect the highest levels of TSH in those with long-term, severe hypothyroidism. (Seems that not only does the pituitary increase in TSH capacity but also prolactin. Hence the reasonably common observation of hyperprolactinaemia, if anyone actually checks.)
For higher levels of TSH, the actual level will not simply reflect how hypothyroid we are in terms of producing thyroid hormone but will be a combination of severity and time.
If we asked how much would TSH rise if someone were subject to sudden loss of their thyroid?, I suspect it would be much lower than 69 or 150 as already mentioned by others. But how low?
The reason this seems especially important is if TSH production capacity limits the rise in TSH even at levels as low as 10. If so, that undermines any guideline which suggests some sort of “don’t treat until” threshold.
Prateek Shukla, Ketan R. Bulsara, Pooja Luthra, "Pituitary Hyperplasia in Severe Primary Hypothyroidism: A Case Report and Review of the Literature", Case Reports in Endocrinology, vol. 2019, Article ID 2012546, 7 pages, 2019. doi.org/10.1155/2019/2012546
hindawi.com/journals/crie/2...
(Obviously the above is both speculative and simplistic. There is no consideration of other pituitary hormones, nor of the hypothalamus and TRH.)
Does this make sense?
Generally the lower thyroid hormones (fT3 and fT4) are the higher TSH goes. I think I've seen patients with TSH in the upper hundreds on the forum. In any event it signifies severe primary hypothyroidism (failing thyroid gland). I suspect how high TSH goes in these circumstances depends on how 'strong' your pituitary is.
The good news is that I've noticed that people who post on this forum with very high TSH tend to disappear from it within a year. I put this down to them becoming well.
Studies that compare TSH to hypothyroid signs and symptoms find a very weak link or no link. In general when TSH is very high there is a clear link with symptoms but when TSH is more moderate the link becomes less obvious. This may be because some people are very hypo with a normal TSH.
Amongst all the other issues, could it be that TSH tests become unreliable at high levels?
Somehow, I have my doubt that most TSH tests have been calibrated and validated when the levels are anw=ywhere near so highas we are discussing.
I think once TSH gets above say 50 the level depends more on how vigorous your pituitary is than how low the hormones are. At lower levels TSH becomes unreliable because if a low or normal TSH is due to insufficent TRH stimulation of the pituitary the TSH has reduced bioactivity. So, TSH is useful but limited. The TSH assay as far as I understand it counts molecules, it doesn't measure TSH bioactivity.
There was somebody here about a year and a half ago , with TSH 4 hundred and something... they were still walking and talking.. but they never came back on.. so i've always wondered if it was assay interference at the lab , rather than a true reading.But other than that one, i don't remember reading of any over about 150 ish.
even 'over 50' seems to be pretty unusual.
When i was diagnosed I was wearing a vest , shirt , jumper and a sheepskin waistcoat under my coat, and a hat, when i went to the doctors with a TSH of 5.7 /6.8 ....it was June/July.
I couldn't string a sentence together, and didn't have the energy to take my coat off, and i'd been increasingly ill for 3 /4 yrs following a birth .... i REALLY don't want to know what TSH 50 feels like .... let alone 150.
Probably doesn't feel as bad as with a TSH of 5.7. When TSH goes high it stimulates the thyroid to produce more T3 and cruically increases T4 to T3 conversion within cells. This is protective. Patients with similar fT4 but non-elevated TSH have much lower fT3 than those with a high TSH. I have a file of over 50 such patients taken from the forum but for confidentially reasons will not post it here. In a way a high TSH is a godsend, you will be diagnosed and will fair better than someone with a similar fT4 (and lower fT3).
Fortunately they found TPOab of 2499 and rechecked and got >3000 (and they had a crack at testing my ankle reflex relaxation speed which was glacial)... or else i don't think they'd have done anything about it.. "i'll check , but it's not going to be your thyroid cos you're not overweight ...." I wish i knew my fT4/3 from then, but they only did a TT4 (29%) which doesn't really tell me much.
In your experience, do you think my TSH will normalise relatively quickly?
TSH usually recovers when normal hormone levels are achieved but when it has been very high it can take a month or two longer, so they have pay attention to your symptoms and fT3, fT4 rather than TSH. You will take several months to get better.
I gave birth in March, it was only because my bloods showed a TSH of 5 after labour I was referred for further TFT. When I had these done 3 months later in June, my TSH was 100, T4 3.03, and I didn't have any overt symptoms. The only symptoms I noted were because I have complete certain checks, I monitor my BTT and noticed my body temperature was cooler than pre birth- but I did not feel cold. I noticed my resting heart rate dropped to an average of 58bpm- but then I was exercising, cycling and walking miles so put it down to fitness. Other than that, I felt well.. not symptomatic as I was advised I should be feeling with a TSH that high and my T4 was 3.03 and antibodies were 498, so they think it is autoimmune rather than post natal thyroiditis.
My bloods are to be rechecked tomorrow so will see what happens.
Try and get fT3 measured also, they may not do it but you can but ask.
Already tried, UK drs don't test for T3 they're only concerned with the TSH, T4 and antibodies.
Always get thyroid levels tested as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test
If taking any supplements that contain biotin you need to stop these a week before all blood tests as biotin can falsely affect test results
Request vitamin D, folate, ferritin and B12 are tested if not already done
Don't worry too much as I am now well and my TSH was 100 too. You can click on my name and it will take you to my background history and it isn't unusual not to be diagnosed. It means that members can click on our names and if the person has completed their page they don't need to repeat it often.
My TSH was 139 at one time, after RAI for Graves. I could barely stand up to get from the waiting room into the surgery!
I have seen people use the fact that TSH can go as high as 100 or more as justification for the mistaken assumption that TSH works on a logarithmic scale. This means that a doubling from 1.25 typically to 2.5 typically is insignificant and it must get to 10 or more before treating.
Hi. My TSH in April was 160 when first tested and T3 under 3. I felt very ill. Trouble swallowing, hoarse, hearing going, swelling, large spare tyre although I was eating very little. My mental health deteriorated so that I had huge panic attacks and severe depression. Then my hair got very thin, my eyelashes broke off and I lost all my body hair. I couldn't get a GP to see me and this had gone on for a year. When the result came back the doc rechecked it in case it was a mistake but 2 weeks later it was 161.5. 3 months later my later the TSH is 35. Still no Dr. The clinical pharmacist at the surgery rang me with the result and I'm now on 75 micrograms levo after starting on 50. Within a fortnight of starting meds I felt better. The spare tyre is gone, hearing better,, swallowing fine, voice restored etc. I know I'm autoimmune as TPO was tested 7years ago and was 400 then although TSH was 4. I've also gone gluten free and a lot of stomach issues have resolved. I managed to work all through this nightmare but I couldn't speak properly sometimes due to swollen tongue and my balance was sometimes unsteady and then the hair loss. It's been a living nightmare but still no proper docs appt.
Thank you for sharing.
Thyroid - How dangerous is it having TSH at 0.01? 
High TSH despite high FT4
High TSH
