it happens even in people without any thyroid, so the lowering of T4 is presumably caused by deiodinases tweaking conversion rates of T4>> T3 , T4 >> rT3 , T3 >> T3 ?
your T3 has probably gone up as a direct result of the higher dose of T3 ?
Yes, I shouldnāt really have mentioned the rise in T3 rate as even though my TSH has dropped (therefore affecting conversion potentially) so I think it makes sense as you say that itās risen due to the increase in medication.
I am still confused by the drop in T4 even tho I am taking more T4ā¦ and it doesnāt make sense that it is simply converting well into T3 because the increase in T3 can be accounted for by the rise in my exogenous T3 dose.
So do you think itās just the DIOs doing strange things that are beyond our understanding?
Thyroid / deiodinase / conversion etc etc ....It's a massively complex system with all sort's of feedback loops that we do know about, and no doubt plenty more that we don't know about 'yet'.
We ALL over simplify it, just in order to try to understand it,
But living organisms do not follow over simplified rules,
In real life the actual answer to 'any' thyroid question is probably "well, it might be a bit of both, with some randomness thrown in, we don't really know "
I don't think anyone has come up with nice neat explanation for the lowering of T4 yet, but even when they do .. for every person who gets blood test results that make the theory look correct, you will find another person with results that make you go "eh ?"
our real life blood test conditions have so many variables to consider that we can't even be certain your T3 has actually gone up ,or your T4 has gone down ..we 'think' they have based on one test, but if you had taken the test 45 minutes later , would the fT4/ fT3 results have come out the same , almost certainly not , if you'd had a walk up a windy hill the day before , would they have been the same . possibly not.
The differences between your T4 and T3 result are small, The accuracy of T4 /T3 testing is compromised by all manner of issues , including the %variation the lab is allowed.
For all you know, if you'd tested 45 minutes earlier , or walked up a big hill the day before the the 2nd blood test , you could be seeing different results and asking "why has my T4 gone up , or why has my T3 not gone up" .
Just when we think we understand something , you can guarantee we will get a blood test back that does the opposite of what we thought we understood .
We don't have 'good enough testing' or 'frequent enough testing' to know what is really going on..... we would need to be in a lab with controlled conditions and test bloods every hour .. we are only ever looking on snapshots of a single moment in time, and the snapshots are taken using very wobbly tripods.
fT4 /fT3 tests give us a good enough picture to know if we are looking at a barn, or a bit of lego , but we cant use them to measure the barn, or the lego.
This reply probably doesn't make much sense , cos somewhere in the middle i forgot what the question was .
i'm only on Levo nothing to complicate the issue , but my fT4 still went UP when i lowered Levo, and DOWN when i increased it ...go figure ... ??
so i'm just trying to say ~ don't read too much 'theory' into one blood test .. even if you think you've made sense of what is happening, the next test will probably prove you wrong .
yes I fully agreeā¦ wouldnāt it be lovely to just get inside a cell and really see it all? Iād love to get my hands on all those organelles etc. Iād imagine my cells need a real tidy up, can really envisage myself organising, labelling, refurbishing etc. ānow this really shouldnāt be hereā¦ how are you going to make any ATP if youāre all the way over there?? And whatās that weird bit of mercury doing in here? And omg thatās lead. Youāre definitely going to need to leave.ā I think Iād also be putting a lot of adipose on free cycle š I hope you followed all thatā¦ mind has gone a bit nutty š
on second thoughts , i don't think i should be allowed to tidy up my cells .. i just remembered what happened last time i "tidied up" some things i didn't understand on my computer .
Iāve also reflected that on second thoughts Iād be quite ashamed to set foot in my cellsā¦ theyāve probably got a lot to say to me about all the Monster Munch I consume.
I know you didnāt ask me but I just thought Iād say that I donāt think there is anything wrong with it, it seems to happen to most people on t3/t4 replacement. My current results just mean I need to increase my NDT. If I reach a place where my T3 is in the top 75% of the range but my T4 is languishing below 30% then I would consider taking T4 with the NDT, which Iād assume would raise my T4 and wouldnāt run such a risk of being packaged off into something elseā¦ assuming my rt3 doesnāt go nuts š
On the same dose of NDT my T3 and T4 blood tests differed year on year and the only differential I found was that my ferritin had dropped some 25% giving me less T3 and a higher T4 reading.
Do not assume if your T4 is relatively low in the range you need to add T4 as you track on the Free T3 anyway -
There is a unique ratio of T3 and T4 in NDT - roughly at around 1/4 T3/T4 which works well for the vast majority of people taking it -
Though I read some people when they are very close to their sweet spot say they need to tweek with a little T3 or T4 but personally haven't needed to and find this sweet spot elusive - as I still have some symptoms of hypothyroidism, but in the overall scheme of things as treatment options go NDT suits me the best.
However we can imagine that if more T3 is available, the body might simply get rid of more T4 - sulphated, glucoronidated, as reverse T3, or any other possible route.
I guess this is the situation where how we feel is paramount?! Off course that is no use to your GP because either they wonāt understand, wonāt listen, reduce or increase medication at random etc. Boy we really need our thyroid education to keep on top of things ourselves but most importantly use the accrued knowledge and experience of everyone in the forum - especially the old hands! Itās harder when you donāt feel well but wonderfully this all seems to be taken into consideration by the āold handsā. So lucky (again) to have found this forum.
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