Views & Reviews From the Frontline

Bad medicine: thyroid disease

BMJ 2012; 345 doi: (Published 09 November 2012) Cite this as: BMJ 2012;345:e7596

Re: Bad medicine: thyroid disease

I do not like the term "sub-clinical" in respect of hypothryoidism. It seems to me that the distinction between sub-clinical and overt hypothyroidism is somewhat arbritary. For the same degree of thyroid function abnormality, the diagnosis depends to a considerable extent on the position of the patient’s normal set point for fT4 and fT3 within the laboratory reference range.

When I was diagnosed with "sub-clinical" hypothryoidism last summer, my TSH was 18.0 but my fT3 and fT4 were just inside the bottom of the reference range. I was told that my symptoms could not be caused by my thryoid, as sub-clinical hypothyroidism is the mildest form of hypothyroidism and by definition has no symptoms. However, my symptoms were very unpleasant (vertigo, anxiety, panic attacks, headaches, tingling in feet and head, feeling disconnected etc.etc.) I had to beg for a trial of thyroxine and was told it wouldn't help me as there was nothing wrong with my thyroid as fT3 and fT4 levels were "normal".

Six months later, whilst on a low dose of thyroid hormone replacement, my TSH shot up to 59.0 and fT3 and fT4 were below range. I had the same symptoms as when my TSH was 18.0 and now I was told my thyroid had failed completely and I now had "overt" hypothyroidism.

Nine months later and I am on a much higher dosage of thyroid hormone replacement and my symptoms have all pretty much gone. I am one of the lucky ones.

It would seem that my original low-in-range fT3 and fT4 results were far too low for me, and that my set-point must be much higher in the range, or even above it (surely some people's set point must actually be above the range by the nature of statistics?). Being low in the range was not "sub-clinical", for me it was very abnormal and I needed treatment.

I think we need to scrap this arbitrary distinction between "overt" and "sub-clinical" and go more by symptoms. Without fT3 and fT4 tests from our pre-hypothyroidism days, and most of us don't have these, it is impossible to know what our original set-point was and therefore what is normal for us.

Treatment should be given and dosage titrated until symptoms are better and if this can't be achieved with thyroxine alone then other treatments options, including T3 and NDT, should be explored. But that is a whole other story.

Competing interests: No competing interests

21 November 2012
EC Elliott