Thyroid UK

How to convince GP to increase Levo when blood tests "normal" range?

A year ago my elderly mum's annual thyroid blood tests were excellent on 100 mcg Levo (TSH 0.2, FT4 22). Since then she has gained several stone in weight, due to taking steroids for a lung condition that makes her very poorly, and I believe she needs an increase in thyroxine. Latest blood tests came back "normal, no action required", despite TSH gone up to 3.32 [0.2 - 5.0] and FT4 dropped to 13.3 [9.0 - 21.0].

Does anyone have any solid medical references that I can use to convince her GP to increase her thyroxine, given that she clearly is clueless about optimal levels? I have the Dr Toft quotes from his "Understanding Thyroid Disorders" book. Anyone got anything else I can use?

Any help much appreciated! xx

7 Replies

Hi First I would try and have a Free T3 test, on line through TUK if GP cannot do it. Often this gives quite a different picture.When I started treatment many years ago, FT3 was always tested and that was below normal , although other things no.

Some times GP will give a tiny dose to see if it helps., she could ask fro a trial for 3 months.There is quite a bit of info on this site. However, GP`s do not like reading info etc so I would make a clear list of the problems and then, read them out to the GP.

I hope that helps.



Thanks Jackie. The difficultly isnt in getting diagnosed (She's been on thyroxine for many years), just need to convince GP that her current 100mcg should be increased. The GP thinks correct dose is to get patient anywhere in normal range, so doesn't care that FT4 is so low in range or TSH been increasing.


Yes I see, I still think the FT3 level could help a lot. You are quite right, the T4 does need to be in top third of range. Is there another GP in the practice you can see? or ask when that GP is away.If TSH is increasing , any good doc will see that FT3 is important as it lowers the TSH. So sks for either an increase in T4 or some FT3 as well for this, with the blood tests. It may work.Otherwise say that you are not happy and want her to see an Endo, but choose one yourself first by careful research.

Best wishes,



Thanks Jackie. I'm going to try to go with mum to next GPs appointment. If I can't get agreement to increase I'll nag for referral as you suggest.


You mean, he can see the rise in TSH and drop in T4 and not recognize something is going wrong. Please remind that she was at optimal levels in the past and now that they have dropped, they are not normal for HER. You really shouldn't need any other proof than that. Look at the TSH, Ft4, and FT3 in this article.


Yes, sounds like crazy logic doesn't it? Interesting info on that link! Thanks Heloise. X


All I can give you is a quote from Dr Toft of the British Thyroid Association. If you need a copy of this Pulse Online article, email

6 What is the correct dose of thyroxine and is there any rationale for adding in tri-iodothyronine?

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.


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