Reference to bring to doctor? Free T4 levels up... - Thyroid UK

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Reference to bring to doctor? Free T4 levels upper limit


Does anyone have any reference that I can bring to doctor to state my case that I need increases until I get to the top of the free T4 range?

She didn't put in my journal that I upped the dose to 100 and then I have had a test and increased once more that she doesn't know of because she was I'll when I had my appointment. I really need her to realise that I need more medication.

Please if someone could post a link or recommend a book stating that you need your free T4 at the top of the range to feel ok. I already have Dr Peatfield's book but can't find anything to show her in there.

4 Replies

This may be helpful for you. You don't need to get to the very top of FT4 but somewhere near it. Of course FT3 is the most important and you can read in the link about why both FT3 and FT4 are required .

Beenies in reply to shaws

Sorry, can't find where it says that levels need to be in your part.


Beenies Besides the link Shaws has provided, there is this under Treatment Options:

"According to the BMA's booklet, "Understanding Thyroid Disorders", many people do not feel well unless their levels are at the bottom of the TSH range or below and at the top of the FT4 range or a little above."

The book is written for the British Medical Association by Dr Anthony Toft, leading endocrinologist and past president of the British Thyroid Association. It is available from pharmacies and Amazon for about £4.95.


Dr Toft states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the article by emailing , print it off and highlight question 6 to show your GP.

Beenies in reply to SeasideSusie

Thank you ordered the book. Hope I will get it before seeing doctor.

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