Confused!: Hi, can I ask what T3 & T4 are?  My... - Thyroid UK

Thyroid UK

140,915 members166,036 posts

Confused!

Mags_23 profile image
13 Replies

Hi, can I ask what T3 & T4 are?  My Mum usually just has her thyroid function bloods tested. Should she be having these done too? We where told her levels are fine, however, she's still very tired all the time. Plus what is a normal range for levels? Thanks in advance.

Written by
Mags_23 profile image
Mags_23
To view profiles and participate in discussions please or .
Read more about...
13 Replies
Anthea55 profile image
Anthea55

Hi Mags_23

Have a look at the ThyroidUK website

thyroiduk.org.uk/tuk/index....

this has loads of information for you.

Here's a quote

'The thyroid gland produces two main hormones which are very important for growth and development. One is called thyroxine (T4) and the other is called triiodothyronine (T3). T4 is converted to T3 in the body's cells and tissues. T3 is an active hormone and is needed by all of the cells and tissues of the body.'

More detail on this page

thyroiduk.org.uk/tuk/about_...

Many doctors treat according to the TSH blood test (Thyroid Stimulating Hormone) but you should also have Free T4 and Free T3 tested to make sure that they are high enough.  TSH can be 'in range' but still far too high.

Ask the surgery for a printout of your Mum's most recent blood tests, then post them on here, with the ranges, then you can get further advice.  We are entitled to be given these results in print, not just the 'it's in range' answer.

I see from your previous post that your Mum has been very ill.  I hope she's beginning to feel better, but anything like that takes a long time to get over, especially as we get older.  She had very poor treatment.  Would it be possible for her to see a different doctor at the practice who might know a bit more about thyroids?

Redditch profile image
Redditch

Right

They  usually test TSH thyroid stimulating hormone. If it's high your bodyi thinks it needs more. 

High is regarded as over 4 for a healthy person but if you have a thyroid issue the normal ranges don't mean anything. I need my TSH to be about 0.5 but we're all different.

T4 is what the body is trying to make and what the most commonly used drug is.

If you tesr the. FREE T4 and it's very low that can mean you need more medication

If the FreeT4 is very high then either you're taking too much medication or it's the wrong medication for your body and you are not getting the benefit.

T3 is what the body runs on. Think of T4 as crude oil and T3 as petrol. We covert or refine our T4 into T3 to make our go go juice.

If your mum has no go go juice she either has no crude oil supplies or the petrol refinery is not worn ng.

FT3 free T 3 is not really a valuable test if she's not on any meds. 

Hope that helps. She should take her temperature every morning and wridown. t down Humans are warm. Thyroid seffereres have low temperatures. That would prove to you both that it is thyroid you are dealing with

Good luck

Mags_23 profile image
Mags_23

Thanks for all your replies, they have been very helpful. Yes Anthea55, your right, my Mum has been very ill indeed, when she came out of hospital she was on 100mg of Thyroxine and was doing good. In January she went to see an Endocrine Consultant who took her bloods & then sent a letter saying her levels where too high & to reduce her Thyroxine to 75mg. Since doing this she has been very sleepy. Im was unsure if it was her levels or maybe just everything she had been through catching up with her. I phoned the hospital on Friday & they told me her bloods where taken last Friday and that "her levels where fine".  I have read on here about T3 & T4 on here, just wasn't sure what it was. I think when we go to the hospital in 2 weeks, I will ask them about testing her t3 & t4.

greygoose profile image
greygoose in reply toMags_23

She needs to ask for a print-out of her results every time she has a blood test, not just accept everybodies opinion of 'fine' or 'ok'. They Don't know what they're talking about, most of the time. She needs to see exactly what was tested, and exactly what the result was. I'm afraid we just cannot trust doctors to know what they're doing when it comes to thyroid.

Mags_23 profile image
Mags_23 in reply togreygoose

But how would I know what is acceptable for her?

greygoose profile image
greygoose in reply toMags_23

I'm sorry, I Don't understand. What levels would be acceptable, you mean? Post them on here and let us have a look.

Mags_23 profile image
Mags_23 in reply togreygoose

What I mean is how would I know what my Mum's levels should be in the first place? As everyone's amount of Thyroxine is different, surely no two peoples ideal levels are the same? We are never given a print out or told what her levels are, just the Endocrine Consultant saying that her levels are fine. (I would assume they would know what they are talking about!)

greygoose profile image
greygoose in reply toMags_23

I would not assume that, if I were you!

Yes, everyone's different. But blood tests have ranges, and if her results are at the bottom of the range, then you know somethings's wrong. It's not just a case of being anywhere in range, as doctors think. It's where in the range that the result falls that counts.

Nobody's ever going to offer you a print out of your results. Often they prefer you Don't know! But, it's your legal right to have one, and you have to ask for it.

The object of thyroid hormone replacement - and this is another thing that doctors, not even endos, seem to know - is to start out low, and increase by 25 mcg Levo every six weeks until all the patients symptoms have disappeared. Is that what your mother's doctors have been doing? If not, they Don't know what they're doing.

If they've just been testing the TSH and adjusting her Levo in such a way as to keep it in range, then they Don't know what they're doing. That is the way to keep a patient sick. Because it's hard to keep the TSH in range AND the frees - T4 and T3 - at a level at which the patient feels well. It's very often impossible. But doctors Don't know that.

You would be amazed at all the things so-called thyroid specialist Don't know. However, if you're convinced the specialist knows what he's doing, I Wonder why you're asking questions on here. I think, in your heart of hearts, you suspect he doesn't. You Don't even know if he's doing the right tests. That's why you should ask for a print out of the results and find out just how much he does know about your mother's condition. Well, I would have thought so, anyway. Because she doesn't sound 'fine' to me.   

Hi Mags_23

Definitely you Mom should get a full blood test. I was neglected for over 15 years by just having my TSH monitored yearly and  being told I'm in 'range'  and not given any meds. I had 2 x Radio active iodine  treatments 20 years ago and suffered loads of illness  over the years because of this neglect. I hope you get some quality help for her and that she will soon be feeling much better. x

victoria1000 profile image
victoria1000

The adrenal gland keep the thyroid in balance. My advice is to read about support for the Adrenal Gland

Eddie83 profile image
Eddie83

T4 is the thyroid storage hormone, which is eventually converted to T3, the thyroid active hormone (the hormone which tickles receptors).   T4 is made by the thyroid gland.  T3 is made by the thyroid gland, and is also made throughout the body (and esp. in the gut and liver) via the T4->T3 conversion process.  If she's being treated by the usual know-little doctor, they are only measuring her TSH, which is not an adequate method of diagnosis.  To really understand what is going on, she must have all of the 6 tests  (at a minimum): TSH FT3 FT4 rT3 TPOAb TGAb.  A doctor who tells you levels are "normal" or "fine" isn't providing you useful information; the number(s) are what matter.

Mags_23 profile image
Mags_23

When she attends the hospital it is a Professor in Endocrine that she sees. When she is next at clinic, I will ask him about the other tests you suggest.

mistydog profile image
mistydog in reply toMags_23

Always question, never accept without valid evidence.  Ask for printouts of all results and then you can come here and get advice, and also once you understand them can compare previous results, spot patterns, see if you were told the full picture.  Professors still have to toe the line so with the best will in the world, they are limited with what they will tell you.

Not what you're looking for?

You may also like...

Confused!

Hi I'm new here, I was diagnosed with an underactive Thyroid and vit b12 def last nov - I've been...
Mmw-15 profile image

Confused

Hi this is my 1st post. Last week I went to see my GP as I was fed up. I walked in with the...
MrsMilzy profile image

Confused

Hello I managed too get gp telephone consultation and gp has advised I reduce b12 s my levels have...
nettiboo1982 profile image

Confused :-/

Hi Im still battling to feel somewhere near normal and have these questions in my head which I...
Tweetypie28 profile image

Confused 🤔

Evening all! I posted on here over a week ago regarding taking a private blood test to check my...
Henson1980 profile image

Moderation team

See all
RedApple profile image
RedAppleAdministrator
PurpleNails profile image
PurpleNailsAdministrator
SlowDragon profile image
SlowDragonAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.