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Thyroid UK
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New Member - Hello! (Body Temperature Advice)


A new member here so hello to you all...!

I would greatly appreciate some advice on my situation if that is ok as I totally puzzled, feeling terrible and whilst I am slowly beginning to think that I am getting to the possible route cause of my issues, I am still very unsure.

In terms of symptoms, for over 5 years now I have been fatigued, muscle pain, digestive upset, weight gain, tinnitus, brain-fog, food intolerances, low mood and various other ailments which have come and gone, the list of which is simply endless. I have been diagnosed with CFS and Fibromyalgia but quite frankly, whilst I am constantly tired and fatigued, I do not believe that my diagnosis is accurate.

I have had many a blood test all of which come back "normal" and now, if I attend my GP, the conversation quickly turns to my "mood" which insinuates that all of the above is in my head - which it is not!

I have gone from being a very fit 40 year old, working out 4 times per week, to frankly a "shell" that struggles to function.

Recently, I decided to take some control and I ordered both thyroid and cortisol tests. I have just ordered a DHEA test and I am taking my blood pressure and body temperature daily.

My results were:


TSH - 1.15 (0.27 - 4.20)

FT4 - 16.6 (12 - 22)

TT4 - 100 (59-154)

FT3 - 5.81 (3.10 - 6.80)

Antibody - 13.9 (0-115)


Waking - 12.2 (6-21)

12PM - 4.48 (1.5 - 7.6)

4PM - 3.83 (0 - 5.49)

BED - 1.5 (0 - 1.99)

As you can see, my above results would appear to be within range and even my basic understanding indicates that my thyroid results are bang in the middle.

However, there are some things which are out of profile.

My cholesterol is 6.78 and high and I have very low amounts of HDL. I assume that this is down to my weight gain and inactive lifestyle due to CFS. I have started walking to address this. My average blood pressure was 137/84 (72) and I have managed to get this down to around 126/80(65) which I assume has been a result of my walking.

The main issue however is my body temperature - it simply will not go above 36c. I am in the region of 35.4 to 35.8 and yet I am confused by my thyroid results above as they appear normal. My adrenal cortisol results are at the low end of "normal" although I feel fatigued and now have low libido - I am exploring whether I am currently going through the "DHEA steal phase" to prop up cortisol levels hence my ordering a DHEA test.

I have bizarrely noticed recently that when taking my son to his swimming lessons and when in the hot pool area, my physical symptoms subside somewhat and my skin feels hydrated once again (not cold and thin). However, the heat fatigues me somewhat. Also, I noticed that my symptoms subsided when I was on holiday in Spain this summer and I wonder whether it is my body temperature that is a major factor here.

I guess my post (apologies for the length) is simply to see if anyone else has experienced low body temperature with relatively normal thyroid / cortisol results and whilst displaying similar symptoms to me - any advice on what to do or how to approach this debilitating condition would be extremely welcomed.

One final point, my symptoms developed soon after I had a large amalgam filling removed and I was exposed to the methyl mercury. I anticipate that there are differing views here on whether mercury is a legitimate line of exploration but it is something that I am aware of and again, I wonder if anyone here has any experience of dealing with heavy metal exposure on thyroid / adrenal / body temperature?

Many Thanks


4 Replies

Tinnitus is one of the symptoms of B12 deficiency. You can be deficient even when in NHS range. Have you had B12, folate, ferritin and vitamin D tested? Very many of us find we have deficiencies associated with thyroid conditions. This is the most likely cause of your symptoms

Taking Levothyroxine can cause some disruption to normal stomach bacteria balance which may cause absorption problems. Even with excellent nutrition we can have deficiencies as a result. All vitamins need to be mid-range and B12 is best top of range.

1 like

Hello HV,

I can understan that you are confused and I would imagine it would be hard to get help from a endo with your results. However, diagnosing hypothyroidism is not very straight forward. In the olden times the diagnosis was done mainly looking at body temp, pulse and cholesterol level. In hypothyroidism your body temp is low, your pulse is low and your cholesterol high. This means that your basal metabolic rate is not optimal and your thyroid that regulates body temp is not working as it should. The fact that your symptoms subside in warm enviroment also speeks for low thyroid function since the thyroid doesn't have to work as hard as in the cold.

I hope gray goose will have thoughts about your blood results. I hope you get things sorted out soon.

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Welcome to the forum, High_Valour.

Your thyroid levels are unequivocally euthyroid (normal). TSH 1.15 is low-normal, FT4 16.6 is mid-range, and FT3 5.81 is in the upper third of range. Thyroid peroxidase antibodies are negative for autoimmune thyroiditis (Hashimoto's).

Cortisol is also within normal ranges.

Although low body temperature can be a sign of hypothyroidism it may also be due to other reasons.

Normal body temperature varies by person, age, activity, and time of day. The average normal body temperature is generally accepted as 98.6°F (37°C). Some studies have shown that the "normal" body temperature can have a wide range, from 97°F (36.1°C) to 99°F (37.2°C).26 Jan 2017

Body temperature norms: MedlinePlus Medical Encyclopedia


1 like


Thank you for your input thus far, much appreciated.

With regard to the queries raised, as it so happens I have recently had my Ferrritin levels checked and they were as follows:

Iron - 27.5 (10.6 - 28.30)

TIBC - 61.7 (41-77)

Transferrin - 44.57 (20-55)

My reading of this is that I have adequate / within range (albeit slightly high) iron circulating in my blood, adequate levels of iron binding capacity and decent levels of transporting protein for iron. In short, I think my iron is ok.

With regard to B12, I had this tested August 2016 and I don't have levels or reference ranges - I simply have a "good/borderline/bad" score (Genova Diagnostics) and my B12 was borderline, my B9 folate was bad. I didn't have Vit D tested.

Can deficiencies in B12, D etc cause low body temperature?

I may get these tested soon and at least see where I am with them and/or rule them out as potential issues. I have had digestive issues for quite some time so it stands to reason that my absorption may have had an impact here.

Thanks again.



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