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Thyroid UK
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Blood result advice please


I have Hashimotos and feel exhausted all the time. Just had routing blood results back and doctor said they are fine.

TSH 4.3 (0.3-4.3) my previous result was 1.3 about10 months ago

T3 4.3 (4-6.8)

T4 16.6 (12-22)

I currently take 100mg of levothyroxine.

Any advice welcomed as I'm so exhausted all the time and few frustrated that the doctor thinks it's in my head!


5 Replies


You are undermedicated to have TSH 4.3 while taking 100mcg Levothyroxine. Ask your GP to increase dose.

The goal of Levothyroxine is to restore the patient to euthyroid status. For most patients that will be when TSH is 0.3 - 1.0 with FT4 in the upper range. FT4 needs to be in the upper range in order that sufficient T3 is converted. Read Treatment Options in thyroiduk.org.uk/tuk/about_... Email dionne.fulcher@thyroiduk.org if you would like a copy of the Pulse article to show your GP.

If your GP won't listen see another GP at the practice or change practice.


Thank you for your help and advice, I haves emailed requesting the pulse article. Hopefully I will find a doctor who takes this seriously

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You are very under medicated. The aim of thyroid replacement hormone is to bring TSH down to around one and FT4 towards top of range and FT3 at least half way in range.

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, 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 articles from Thyroid UK email dionne.fulcher@thyroidUK.org. print it and highlight question 6 to show your doctor.

Would suspect your vitamin D, folate, ferritin and B12 may also be too low as you are under medicated

When these are too low they can stop Thyroid hormones working

Ask GP to test these, if not been done. Or post results and ranges if you have them

Make urgent appointment and ask for 25mcg dose increase in Levo, retesting after 6 weeks.

All thyroid tests should be done as early as possible in morning and fasting and don't take Levo in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results

About 90% of all hypothyroidism in Uk is due to Hashimoto's

Hashimoto's messes with our gut function, lowering stomach acid and causes low vitamin levels

Poor gut function can lead leaky gut (literally holes in gut wall) this can cause food intolerances. Most common by far is gluten

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

But don't be surprised that GP or endo never mention gut, gluten or low vitamins. Hashimoto's is very poorly understood

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies







Box 1 near end of link lists vitamins that affect thyroid (if GP says why?)


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Thank you so much for your help, I will get a copy of the pulse article and take it to my doctors. I have just ordered Izabella Wentz book so hopefully I will better educated to challenge my GP.

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Your TSH is probably too high for someone being treated, a consultant told me the upper limit was much lower when u are on T4.

I have a T4 conversion problem as many do and they keep my TSH below 1!

Important you get full suite of tests if you can.



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