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How can TSH rise and T3 stay the same.


I posted 2 days ago and got a couple of replies, one suggesting to get my nutrients checked and the other to say maybe to try and increase NDT by quarter grain every third day.

Today I am sat here thinking that if one of my nutrients are low this may explain why my TSH had risen, but what I do not understand is why my T3 has stayed the same.

(please see post below)

Does anyone know why a TSH can rise but T3 stay the same.

Thank you

Posted 13th January 2017

Just got my results from G.P.

I am presently taking 1.5 grains W.P. Thyroid.

TSH - 3.2 range 0.35 - 4.7

T4 - 6.8 range 7.8 - 21.0

T3 - 5.1 range 3.8 - 6.0

Last results July, 2016

TSH 0.42

T4 7.6

T3 5.2 All same range as above.

So TSH has risen by quite a lot and T4 reduced and T3 pretty much the same,

I knew something was not right as I have felt quite a few symptoms return these past few weeks.

I feel more tired, anxious, B.P. has risen, carpel tunnel is back, itching, indigestion, constipation calf twitching and cramps.

When I tried to increase to 2 grains a few of months ago I got a bad reaction so reduced back to 1.5 grains. I then tried increasing quarter of a grain a few weeks ago and I immediately got palpitations which stopped when I stop the quarter.

So what do I do now.

I am wondering if adding in some T4 may help as I obviously cannot increase the NDT. or should I have everything else checked, first, ferritin, folate, B12 and Vit D. in case any of the levels have fallen, (mainly Vit D. because of the time of year) and these are stopping my NDT working properly, although I do supplement and at last tests all were reasonable.

Any thoughts anyone.

Many thanks.

13 Replies

Have you had your antibodies checked at all? I am not certain but would assume if these go high then tsh could also x



thank you for your reply, yes they are both in range but high in range so Doctor says I do not have hashi's.


Hi Lucy, the fact that your T4 is lower on what I would presume is the same dose, would suggest that your absorption is declining. If you are taking it at the same time of day, with the same gap to any food/drink and supplements, then that may suggest a worsening in either your stomach acid/digestive enzymes or gut health. Have you had any anti-biotics in the intervening period? Have you started any acid blocking drugs like ranitidine or ppis? Looking at your relative figures your conversion has not worsened despite your lower T4 level. But that lower T4 level means that your system is having to work harder to produce the same amount of T3, hence I would presume the higher TSH level.

The inability to raise T3 is a different issue and might suggest an adrenal problem. I am not an expert on that, but I am sure someone who is will be along shortly.

I hope you get somewhere soon

Good luck

Gillian xx


Thank you Gillian for your reply,

I have not taken any anti-biotics or any other drugs.

The only thing I can think of is, over the Christmas period I may have not taken the second tablet of the day on an empty stomach, with eating more over this time. I wonder now if this has caused absorption issues.


Were both tests done at the same day, and under the same circumstances?

You cannot rule out Hashi's on one negative test, because antibodies fluctuate. Especially as yours were high in range.

I really don't think the difference in your results has anything to do with absorption problems, because if it were that, your FT3 would also be affected.

I think you really should see to your nutrients before you make any more attempts to increase your dose (and certainly don't try increasing every three days!).


Many thanks GG for replying.

yes tests were done on the same day at 9.15am, I fasted and took last dose of NDT 17 hours before test.

Now wondering if my Vit D has dropped even though I do supplement. If it has, or any of the other nutrients have, would this explain a rise in TSH, but even if it does then I would have thought T3 would have altered also.


I am just wondering if you were actually told the antibodies result by your doctor or if you saw the results printed yourself for antibodies? Call me synical but I personally wouldn't trust that general statement, ranges for antibodies tend to go really quite high. For example I don't have raised antibodies as mine were at 14 but the range went up to 115. I'd be concerned if they were at 114 as although in range they are significantly elevated.



I did the antibody test through Blue Horizon.

TPO 27.5 <34

TG 95.4 < 115

so both in range but both high in range.

1 like

Yes it looks that way. Make sure you keep an eye on those incase they climb anymore or have since x

1 like

You might find the answer in this post: tiredthyroid.com/blog/2014/...

"Even if someone has suboptimal T4 levels, they could still have sufficient T3 (the more active thyroid hormone) if their TSH is high enough to keep T4 to T3 conversion up. "

FYI, I feel best when I combine NDT with T4. T4 has its own properties that you can't get from direct T3.



I have been looking at tiredthyroid.com

I think I may need to add some T4.

I presently take 1.5 grains NDT so not sure whether just to add some T4 or reduce the NDT and add some T4, any ideas would be appreciated.


Given that your T4 is low and TSH is on the high side, it might make sense to try adding just a little T4. Start with the smallest dose of T4 available, or even cut that in half.


Thank you,

I may try 12.5mcg to begin with.


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