Can someone explain this!

[Dadof5]

Looking at the result section of ths NHS app I came across this in my TSH section and I'm not sure what it means

"excluding patients who are hypopit where treatment is based on FT4 levels"

Can anyone explain this in laymans terms LOL

Cheers

[SlowDragon Administrator]

it means if hypo pituitary……in which case go by Ft4 and Ft3 results ….because pituitary isn’t working and TSH is pituitary hormone

But in practice ANYONE on levothyroxine, or especially if on levothyroxine plus T3, or NDT should always be dosed by Ft4 and Ft3 results…..never by TSH

[SlowDragon Administrator]

Have you had dose increase in levothyroxine yet

Or got vitamin D, folate, ferritin and B12 levels tested yet

[Dadof5 in reply to SlowDragon]

As I put in my other post today I only saw the doctor this morning and getting bloods done on Tuesday.

[SlowDragon Administrator in reply to Dadof5]

sorry missed that that post was also today

Book appointment for 8.45am if possible

Last dose levothyroxine 24 hours before

[Dadof5 in reply to SlowDragon]

Unfortunately because I have to do the school runs had to book for 0920.

[SlowDragon Administrator in reply to Dadof5]

Ok

Obviously NHS medics are totally fixated on TSH and TSH quite likely lower when on metformin

Come back with new post once you get results

[helvella Administrator]

TSH is made by the pituitary gland. (Specifically, the anterior pituitary.)

If the pituitary isn't working "properly", it will not produce the expected amount of TSH. Thus, someone who has an otherwise perfectly functional thyroid gland will become hypothyroid.

A non-functioning, or partially functioning, pituitary gland is known as hypopituitary.

If you measure TSH, it could be within range or low even in people who are very hypothyroid.

Therefore, you should check the actual thyroid hormones - Free T4 and Free T3 - to assess them.

It is possible for people to only be deficient in TSH or to have more extensive pituitary problems - when they can below in multiple hormones.

Hypopituitary can result from several causes including trauma (such as a blow to the head), autoimmune pituitary disorder, or for no known reason.

The really BIG issue is that no doctor will think to test FT4 and FT3 in someone who hasn't got obvious thyroid issues - and most often, high or low TSH.

Really, they should say that the person should be checked for hypopituitary before using a TSH test and its result. But this results in a classic logical craziness. You don't know not to rely on TSH until you know the pituitary is OK which can only be checked by measuring FT4 and FT3!

And once you have done FT4 and FT3, there is little remaining reason to test TSH.

[Dadof5]

Ok I think I understand now. Thank you.

[helvella Administrator]

More or less - yes.

The pituitary will carry on making TSH based on the amount of thyroid hormone on the bloodstream - and how much TRH is sent from the hypothalamus.

TSH will rise and fall similarly to how it does in someone with a thyroid.

Of course, there is no thyroid to respond to the TSH!