Thyroid function test results: Hi Can anyone help... - Thyroid UK

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Thyroid function test results



Can anyone help me understand my Thyroid function test results?

I went to see my GP 4 weeks ago to discuss referral to an endocrinologist as I have suspected for a long time there is something going on with my thyroid in spite of all tests coming back normal. I also wanted copies of previous test results to see if there had been an ongoing problem that was getting worse.

The GP was extremely defensive. 'What on earth do you think an endocrinologist is going to do for you, you are overweight there is no miracle cure'. What do you want your test results for, we don't give test results out …(?!).

Fortunately I managed to get him to agree to do another Thyroid function test, although he thought it was a waste of time.

The results are now back and after checking on the surgery website, I discovered you can get print outs of your test results and a very helpful, kind receptionist provided me with a copy.

They are as follows:

Thyroid peroxidase antibod lev - (JA) - Normal <4 IU/mL <35.00U/mL

Thyroid function test - (JAT) - Normal

Serum free T4 level 11.3 pmol/L 10.30-24.50 pmol/L

Serum TSH level 2.31 mlU/L 0.30-5.50mlU/L

The blood test was done in the afternoon and was non-fasting

Can anyone help me understand what this meant?

Thanks for your help :)

5 Replies

When I read results like yours - as will many on this forum, sighed heavily as it is obvious your GP knows little. He should have also tested your Free T3 which is the most important number but few do.

Your FT4 - Serum free T4 level 11.3 pmol/L 10.30-24.50 pmol/L - is at the bottom of the range when it should be nearer the top. T4 converts to T3 and it is T3 which is the only ACTIVE hormone which drives our whole system from head to toe. I read yesterday that the thyroid gland would be classified as the second brain!

The fact that your blood test was not a fasting one, and blood not drawn at the very earliest, this result will not be true.

Also because your TSH level is 2.31 he has been instructed not to prescribe until the TSH reaches 10 !!! That is the advice given to GPs in the UK but if we lived in other parts of the world, we'd be diagnosed if TSH is over 3.

I'd advise getting a private test from one of our labs, they do home finger pin-prick blood tests and make sure you are well-hydrated a couple of days before.

You only need TSH, FT4 and FT3 and others will come along and advise if I'm incorrect.

Your doctor should check B12, Vit D, iron, ferritin and folate as deficiences also cause symptoms.

Mugswell in reply to shaws

Thanks so much for your reply, it has confirmed my suspicions.

When I insisted on the blood test I did ask for T3 levels to be tested as well. The GP was again very defensive and said of course they test for T3, what was I going on about. He also said I did not need to fast prior to the test and could go along anytime. As you can see, no T3 result!

I really don't want to go back to the GP and have another battle on my hands, it is wasting important time. I have already ordered a home test as you suggested and am seriously considering seeing an endocrinologist who has been highly recommended to me privately.

I have been tested in the past for Vit D and was found to be deficient so take a good supplement every day along with all B Vitamins.

Thank you for helping me come to an informed conclusion!


Hi Mugswell

Serum TSH level 2.31 mlU/L 0.30-5.50mlU/L

Your TSH is a bit high for a "normal, healthy" person. One would expect to see that below 2. Also, if it had been done first thing in the morning, before food, it would be higher. This shows your thyroid is probably beginning to struggle. This is not a thyroid hormone, TSH is a signal from the pituitary to tell the thyroid to make hormone when it detects there isn't enough.

Serum free T4 level 11.3 pmol/L 10.30-24.50 pmol/L

Your FT4 is very low in range. This is a thyroid hormone - free thyroxine (FT4). You have hardly any free thyroxine circulating, this will mean that you will have hardly any free T3 (FT3) either. T4 converts to T3 which is the active hormone which every cell in our bodies need. Low T3 brings symptoms (of hypothyroidism) and weight loss is difficult.

There are a couple of things you can do, which I would suggest you might want to see a different doctor about.

First thing, I would get a full thyroid/vitamin panel and you may not be able to get everything done through your GP. What you need is




Thyroid antibodies - both TPO and TG

Vit D




So if you haven't had all those done then you can get them done with a private test from one of our labs. Best value at the moment is Medichecks Thyroid UltraVit because if you order before the end of October and use code MED99 you get 20% off the current price

Do the test as early as possible in the morning, no later than 9am, fast overnight (delay breakfast until after the test) and drink water only until after the test. You can do this test as a fingerprick test, or if you prefer you can arrange a venous blood draw at extra cost.

Post your results on the forum (with reference ranges) and we can comment.

The other thing is, and this applies if your Medichecks test comes back with an in-range TSH and low FT4, is to ask your doctor to look into Central Hypothyroidism. This is where the problem lies with the pituitary (Secondary Hypothyroidism) or the hypothalamus (Tertiary Hypothyroidism) rather than with the thyroid gland. When TSH is low, normal or slightly elevated, with a low FT4 and symptoms of hypothyroidism, this can suggest Central Hypothyroidism.

Your GP can look at BMJ Best Practice for information - here is something you can read without needing to be subscribed

and another article which explains it

You could do some more research, print out anything that may help and show your GP.

As Central Hypothyroidism isn't as common as Primary Hypothyroidism it's likely that your GP hasn't come across it before. You may need to be referred to an endocrinologist. If so then please make absolutely sure that it is a thyroid specialist that you see. Most endos are diabetes specialists and know little about the thyroid gland (they like to think they do and very often end up making us much more unwell that we were before seeing them). You can email Dionne at

for the list of thyroid friendly endos. Then ask on the forum for feedback on any that you can get to. Then if your GP refers you, make sure it is to one recommended here. It's no guarantee that they will understand Central Hypothyroidism but it's better than seeing a diabetes specialist. You could also ask on the forum if anyone has been successful in getting a diagnosis of Central Hypothyroidism, possibly in your area which you'll have to mention of course.

Thank you so much for your very comprehensive reply.

I am definitely following your advice to get further blood tests done and will post the results on the forum.

With regard to my GP, I feel I have come to the end of the road. He is very defensive and not open to discussion or being given information on the subject - it is all waved to one side with the offer of sending me to a weight control clinic ….

I have been giving the name of a thyroid specialist who has really helped a friend of mine. I live in Orpington, Kent and he works from the Chelsfield Hospital. (edited by Admin). I would have to see him privately.

However first I am going to get the additional blood test done, see what the results are and then go from there.

Again, thank you for your help and advice.

SeasideSusieAdministrator in reply to Mugswell


Definitely do the full testing first, and get some feedback from members on your results. Do that before spending any money on a private doctor.

Also, you could ask on the forum if anyone has any feedback on that particular doctor. Make a new post, you can name him in the thread title to attract the attention of anyone who may have information, but as we can't actually discuss individual doctors on the forum any replies will have to be by private message and your post will be closed so that no-one puts information on the forum.

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