Blood test results help - Low T3 and T4 - Thyroid UK

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Blood test results help - Low T3 and T4

liaratsoni profile image

Hi everyone!

I made a post the other day about my symptoms, deficiencies/bottom of range B12, ferritin and Vitamin D and have since done the medichecks thyroid check blood tests. Test was done fasting at 9.30am. The results are as follows:

TSH: 1.9mlU/L (0.3-4.2)

T3: 3.1pmol/L (3.1-6.8)

Free Thyroxine: 13.1pmol/L (12-22)

Thyroglobulin antibodies <10klU/L (0-115)

Thyroid Peroxidase antibodies <9klU/L (0-34)

As you can see no antibodies and normal tsh but my T3 and T4 are at the bottom of the normal range. Could this be related to my symptoms? I have seen a little about the pituitary gland and it’s control of thyroid stuff as well as adrenals and hormones and as mentioned before I have huge trouble with fatigue, amenorrhea, digestion and other symptoms like extreme cold, deficiencies, yellow skin and tinnitus. As mentioned I’m also on B12 injections which have helped with energy and other symptoms. I am feeling very lost with so many results coming back at the borderline of the normal range and doctors are no help at all due to me being in range. It was a fight to get b12 injections even though I clearly need them due to the improvements they brought. Does anyone have any experience with this? Thank you.

14 Replies

Many need TSH at 1 or lower. Your FT4 and FT3 are low. You need an increase in thyroid medication if you are taking any.

liaratsoni profile image
liaratsoni in reply to Lalatoot

I am not currently taking any medication as this was my first thyroid profile as part of an investigation into possible hypothyroidism. Do you think this is worth bringing to my doctor? Thank you! :)

Lalatoot profile image
Lalatoot in reply to liaratsoni

Read what grey goose has to say. She is one of the experienced ones on here. What she says partic about having to make your case is correct.

In that case it looks as though it could be central hypothyroidism (where either hypothalamus or pituitary don't send the right signals so you don't produce enough thyroid hormone) GPs don't understand it and think it is very rare,. You need a referral to an endo with a clue. It is very hard to get a diagnosis

This looks like Central hypo. Central hypo is when the fault lies with the pituitary (Secondary Hypo) or the hypothalamus (Tertiary Hypo), rather than the thyroid itself (Primary Hypo). Doctors know nothing about this - especially not GPs. So, you are going to have to do your homework and present your case to them, in order to be referred to an endo for further testing.

Here's an article to get you going:

There's much more out there if you google it. You can also have a look through past posts on TUK:

But, one thing is clear: an FT3 of 3.1pmol/L (3.1-6.8) is not 'normal', no matter how they spin it. :)

liaratsoni profile image
liaratsoni in reply to greygoose

Thank you so much for the response! As the fault lies with the pituitary gland I assume this could clearly be linked with my PCOS too. Thank you for the articles and posts too I will be reading through them all to beef up my knowledge! At this point having to persuade the doctors to treat me has become the norm. I had to take a stack of papers on Pernicious Anemia to see a third doctor about my symptoms before she agreed to start injections! Hopefully she will listen to my case again. I was thinking the exact same about the T3 especially. Thank you again for the help! :)

greygoose profile image
greygoose in reply to liaratsoni

You're very welcome. :)

Wasn't FreeT3 tested ? Unusual.

I hadn't even heard of free T3 until you mentioned it and at this point I am unfortunately not surprised it wasn't tested as my experience with doctors has like almost everyone on here been terrible.

Your low-ish FT3 and FT4 remind me of how my lab results looked - and GP's and Endocrinologists all said it was absolutely fine, perfect, normal, good, etc.

I now take NDT and T3 but haven't done a lab test in a while.

liaratsoni profile image
liaratsoni in reply to Londinium

Thank you for your reply! I seem to have been really lucky with the endo I went to - he straight away said my results and symptoms indicated central hypothyroidism. He ran the tests again and my T3 and T4 had both lowered again in a matter of weeks - my T3 was 3 and T4 was 12.8 so he diagnosed me with central hypo and started me on medication.

Hello! Sorry to resurrect an old thread but I noticed that your original results are very similar to mine! Do you think it's worth trying to get a referral, or will I struggle because technically everything is in normal range? I have some symptoms indicative of thyroid issues. Here are my results:

TSH - 2mlU/L (Range: 0.27-4.2)

Free T3 - 3.5pmol/L (Range: 3.1-6.8)

Free Thyroxine: 12.6 pmol/L (Range: 12-22)

Thyroglobulin Antibodies: <10 kU/L (Range: <115)

Thyroid Peroxidase Antibodies : <9.0klU/L (Range: >34)

I also have a folate and Vitamin D deficiency. I'd be so grateful for any advice! Thanks in advance.

Hi there!

I think its definitely worth it - your T3 is only 11% through the range and your T4 only 6% when in a normal person they're both usually around 50% with T3 5-10% higher than T4. My sister had a very similar presentation as you with a higher T3 and started a trial so an endo who understands secondary hypothyroidism should treat you. Unfortunately not all do but you clearly need treatment as I imagine you feel pretty rough! Hope this helps :)

Thank you VERY much for your reply. This is so helpful. I haven't had any luck with GP so far as technically, everything is within the normal range (although far from optimal). I've emailed a private doctor who specialises in thyroid and pituitary disorders so maybe she will have some insight?! We'll see - but I now have the confidence to pursue this further, thanks to you! Much appreciated and all the best to you and your sister.

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