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Thyroid UK
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TSH, FT4 & FT3 normal! (?)

I had my first blood test 2 months ago, where my TSH was on the high side, but my FT4 and FT3 were on the low side. The doctors insisted that my readings were "normal". I tested again 1 month ago for TSH only (as the Endo absolutely insisted that FT4 and FT3 are not useful measures)

and my TSH came down to 1.9. Ive just tested again (same lab) under my own initiative and all my readings now appear to be approaching optimal. TSH=1.7, FT4=3.4, FT3=10.6. However, in some respects, I'm feeling worst than I was 2 months ago.

I have NDT on order, but its still stuck in customs. Ive fine tuned my lifestyle: stopped smoking, alcohol, refined carbohydrates, increased fruut and veg and been supplementing with licquorice...

Im baffled as to why my thyroid values have changed so much, but Im still feeling awful! My basal and average temperature are still around the 36.6°c mark (low), but the doctors brush this off as "normal". I have TPO and Tg antibodies of about 20 (low)

I'm now wondering as to whether I might have a T4/T3 conversion problem or a T3 uptake problem... Anyone know how I can determine this?

Love to you all!


5 Replies

Well, to be honest, it doesn't really sound like your levels have changed very much at all. But, impossible to tell as you don't give all the numbers. Just saying 'high' and 'low' is meaningless.

The two numbers you have given for FT4 and FT3... a) I think you've muddled them up - an FT4 of 3.4 would be extremely low, and an FT3 of 10.6 would be extremely high, but we can't know if this is the case because b) you haven't given the ranges.

So, all in all, we're none the wiser, and can't really help you without a lot more precise information. Sorry. :(


Sorry for my sloppiness and incompleteness (I'm writing on my smartphone):

June: TSH=3.26mIU/L, FT4=0.98ng/dl, FT3=2.63pg/ml

July: TSH=1.91microU/ml, AntiTg=15U/ml, AntiTPO=28U/ml

August: TSH=1.74microU/ml, FT4=10.6pg/ml, FT3=3.4pg/ml


I'm sorry, but you still haven't given the ranges. The results without the ranges are meaningless because they vary from lab to lab.

Were all the tests done at the same time of day and fasting? TSH varies throughout the day, being higher first thing in the morning, and dropping throughout the day. It also drops after eating. So, if they weren't all done under the same circumstances, you can't really compare them.

If you have two consecutive tests with TSH over 3 and low Frees, then you are hypo. But UK doctors won't diagnose you until your TSH is much higher - sometimes over 10! It's a nonsense, but that's the way it is. :(


I tested again 1 month ago for TSH only (as the Endo absolutely insisted that FT4 and FT3 are not useful measures)

The Endo you saw was an idiot. Without Free T4 and Free T3 there is no way of reliably checking for central hypothyroidism.

I would guess that the Endo was a diabetes specialist and knows nothing about the thyroid.


Just to complicate matters labs use different machines for reading bloods so ranges aren't the same throughout the UK. It takes a while to get the hang of things but ranges always follow the results - Example

FREE T4 12.7 (12 - 22)

It is a learning curve I am afraid. When you are having having a blood test for thyroid hormones, it has to be the very earliest appointment, fasting (you can drink water) and if you were taking thyroid hormone replacements you'd allow a gap of 24 hours between last dose and test and take it afterwards. This gives the best reading as TSH is high early a.m. and drops throughout the day. Your doctor should check for thyroid antibodies as these are the cause of the commonest form of Hypothyrodism (aka Hashimotos). If high you should be given levothyroxine.


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