Thyroid UK
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Would like advice about taking basal body temperature

Dear All - have just joined forum. I am a 56 year old male and was diagnosed with ME/Fibromyalgia 14 years ago and have not improved. Recently a friend with thyroid issues (hypothyroidism) suggested I look into 'hidden' thyroid issues which don't show up in blood tests. My symptoms are similar to thyroid sufferers:

Mood swings

Feeling like garbage in the morning (aching, terrible difficulty moving at first, symptoms like a monumental hangover -I don't drink!).

Sudden intense exhaustion, brain fogs.

Of course this could all be purely M.E related and i know that thyroid issues in men are less common but I would like to check basal temperature as I have heard that is considered reliable. I'm still poorly informed about the thyroid and get my hypos/hypers mixed up and don't get all the t3/t4 issues! First issue, though, is what sort of thermometer to use. I've read that digital ones are unreliable but would prefer not to buy mercury unless I have to. I'm aware that there are other 'liquid' thermometers out there but are they reliable as mercury as the accuracy issue seems to be crucial.

Sorry to waffle a bit-any advice much appreciated.


6 Replies


To monitor basal temperature you should have the thermometer beside your bed so that you can take your waking temperature before you sit up or get out of bed to use the bathroom. I'm not sure you can still buy mercury thermometers. There are posts discussing thermometers in this link and BBT in this link

Low temperature used to be one of a number of clinical symptoms used to diagnose hypothyroidism before blood tests were devised but it was never the sole reason a diagnosis was made. Basal temperature is not more reliable than blood tests.

If you post your recent thyroid results and ranges (figures in brackets after results) members will advise whether you are hyperthyroid (over active), hypothyroid (under active) or euthyroid (normal).


Surprised basal temp is not mentioned. I don't think that list is particularly exhaustive! There are many more signs and symptoms of hypothyroidism. The one that made me laugh is the speaking voice/singing voice. I'm sure in the right clinical setting it may work, but my Dr doesn't listen long enough to grade me. And I've never sang to her!


Yes you're probably right. Haven't read that book. Is it worth reading? I seem to recall it gets good reviews.


Thanks will take a look :)


Thanks for responses - now I'm not sure whether BBT is worth doing! perhaps I should start with a blood test covering all the areas. Is the best thing to use a Blue Horizon test -they offer three levels of testing, would it be best to go for the most detailed? Sorry to ask such basic questions, my knowledge is very limited.



Blue Horizon Thyroid Plus 6 tests TSH, FT4 and FT3. Thyroid Plus 11 is more comprehensive including thyroid antibodies, vitamin and mineral tests.


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