thyroid

[Shelaghb]

what exactly is t3? I am taking lethyroxine 75mg daily.

[helvella Administrator Thyroid UK]

The thyroid produces two main hormones - they are often referred to by their short abbreviations - T4 and T3.

The same abbreviations are also used for those hormones when used as medicines.

T4 is also called thyroxine, levothyroxine tetraiodothyronine.

T3 is also called liothyronine, triiodothyronine.

The difference is that T4 has four atoms of iodine and can be converted to T3 which only has three atoms of iodine by removal of the extra iodine atom.

My Vade Mecum has lots of information about such things including diagrams.

The standard view is that the thyroid produces mostly T4 and that is all anyone needs. This has long been regarded as too simple and ignoring evidence by patients. It does appear that the importance of T3 is now very slowly starting to be accepted.

helvella - Vade Mecum for Thyroid

The term vade mecum means:

1. A referential book such as a handbook or manual.

2. A useful object, constantly carried on one’s person.

Please don't get put off by the number of pages!

Nor by the fact it is targeted at people interested in thyroid issues. Much of its contents could be of use to many involved in health issues. Things like abbreviations, lists, general reference information, an Appendix of links to many useful websites.

And do keep up to date. I edit it frequently- sometimes trivially, sometimes extensively. If your copy is more than a few weeks old, please download it again. (You must download - not just view in a browser- for the Table of Contents to work.)

In particular, it is not intended that you sit and read the document. Just that you download it and know you can look things up.

If there is anything you'd like me to add, let me know.

From Dropbox:

dropbox.com/s/vp5ct1cwc03bl...

From Google Drive:

drive.google.com/file/d/1P9...

[SlowDragon Administrator in reply to helvella]

The difference is that T4 has three atoms of iodine and can be converted to T3 which only has three atoms of iodine by removal of the extra iodine atom.

helvella

Think you meant …….”T4 has four atoms of iodine”

[helvella Administrator Thyroid UK in reply to SlowDragon]

I did indeed and will go back to correct1 I re-worded the sentence and missed that.

Thanks

[PurpleNails Administrator]

The thyroid gland produces two main hormones.  It mainly creates thyroxine (T4) and a tiny quantity of triiodothyronine (T3).  Part of the 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.

So when when doctors test for thyroid they should really test the free unbound levels of FT4 & FT3.  

If thyroid levels are abnormal low the TSH (thyroid stimulating hormone) a pituitary hormone which signal thyroid usually becomes high to signal more thyroid needed.  

Doctors are taught the TSH thyroid stimulating hormone it the main marker for thyroid function but it’s not entirely reliable. 

You take a synthetic replacement T4 Levothyroxine or LT4 and if all it well your body will convert adequate levels to T3. 

If someone had good FT4 but poor FT3 they would benefit from synthetic liothyronine or LT3.   

Natural desiccated thyroid was the original treatment & would contain both elements, but has now been entire replaced but LT4 in mainstream treatment.  synthetic Liothyronine T3 is in theory available “if clinically needed” but the criteria is such that it’s virtually prohibited.  

75mcg isn’t a high LT4 dose 1 step up from starter.

Have you had recent levels checked?

[SlowDragon Administrator]

75mcg is only one step up from starter dose levothyroxine

Unless extremely petite likely that might not be high enough dose

How do you feel

Notice in previous post you were diagnosed as low B12 a year ago …..suggests possibly not on high enough dose levothyroxine

Are you now on B12 supplements or injections

What other vitamin supplements are you currently taking

Which brand of levothyroxine are you currently taking

Many people find different brands are not interchangeable

Teva is only brand that makes 75mcg tablets and Teva upsets many people

Bloods should be retested 6-8 weeks after each dose change or brand change in levothyroxine

 

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested.

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

About 90% of primary hypothyroidism is autoimmune thyroid disease, usually diagnosed by high thyroid antibodies 

Autoimmune thyroid disease with goitre is Hashimoto’s

Autoimmune thyroid disease without goitre is Ord’s thyroiditis. 

Both are autoimmune and generally called Hashimoto’s.

Low vitamin levels are extremely common when hypothyroid, especially with autoimmune thyroid disease (Hashimoto’s or Ord’s thyroiditis)

20% of autoimmune thyroid patients never have high thyroid antibodies and ultrasound scan of thyroid can get diagnosis 

In U.K. medics hardly ever refer to autoimmune thyroid disease as Hashimoto’s (or Ord’s thyroiditis)

Recommended on here that all thyroid blood tests early morning, ideally just before 9am and last dose levothyroxine 24 hours before test 

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

List of private testing options and money off codes

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

NHS easy postal kit vitamin D test £29 via

vitamindtest.org.uk

Only do private testing early Monday or Tuesday morning. Watch out for postal strikes, probably want to pay for guaranteed 24 hours delivery 

[Shelaghb in reply to SlowDragon]

I have B12 injections quarterly and my thyroxine make is Teva. I am always light headed these days and my joints ache

[Regenallotment]

hey Shelaghb,

It sounds like you could benefit from a dose increase. It’s £26 to get a blood test with Monitor my health with the TUK discount.

Worth seeing what your levels are and seeing if an increase would help you.

Balance issues are familiar for me too.

I’m on Teva and it suits me (I seem to react to lactose in other brands).

Hope this helps 🦋💚🦋