A small question about blood results.

[Souzy]

I'm currently waiting for the results of my full thyroid panel from Medichecks but in the meantime I had my latest blood results from my GP and I have a small question.

I had the thyroid function test (comprising two tests) done this year and last year and here are the results.

Last year: 04/06/21

Serum Free T4 level: 16 pmol/L (range 11.0 to 23.0)

TSH level: 3.9 mU/L (range 0.27 to 4.5)

This year (08/08/22)

Serum Free T4 level: 16 pmol/L (range 11.0 to 23.0)

TSH level: 1.6 mU/L (range 0.27 to 4.5)

For background, I have a goitre, thyroid peroxidase antibodies at 152 (range <34) and various vague symptoms.

My question is whether it is good, bad or indifferent that while my TSH level has been steadily decreasing over the course of the year, my T4 has stayed steady?

I've had 7 TSH tests and all but one has been a reduction on the one previously, I've only had the two T4 tests though. The tests are all done prior to 9am and I have not eaten or drunk anything prior except a glass of water (because they are so early, not because I've been asked to fast).

Thanks in advance.

[SlowDragon Administrator]

The longer you remain hypothyroid, the further vitamin levels drop, the lower TSH drops

With high thyroid antibodies (hashimoto’s) TSH is especially unreliable

You need coeliac blood test done if not already on strictly gluten free diet

[Souzy in reply to SlowDragon]

Thanks SlowDragon

My endo has said he will be arranging a coeliac disease test so I am waiting on that. I will try a gluten free diet whatever the outcome but a diagnosis will be helpful to persuade family that there is a serious need so I am going to be eating gluten until that test.

Apparently I am euthyroid so I am not considered hypothyroid at the moment but they are monitoring the TSH situation. As I have many vague symptoms a nurse practicioner asked for a T3 and T4 test to be added to the TSH last time but the lab refused the T3 one as I am in range for TSH and T4.

Luckily I had decided to do the full thyroid panel from Medicheck before that blood test so should have that result early next week. It includes some vitamins so I intend to start a vitamin regime once I know those results.

I was just curious that the T4 is steady while my TSH is going down - I had thought they had some kind of relationship - eg if TSH goes up, so does the T4.

[SlowDragon Administrator in reply to Souzy]

Once we start on levothyroxine TSH frequently reduces low or suppressed

Taking a relatively large single dose levothyroxine once a day is not how a correctly functioning thyroid would work

Extremely common to have low Ft3 on just levothyroxine

For good conversion of Ft4 to Ft3 we need OPTIMAL vitamin levels, frequently gluten free and/or dairy free

Just testing TSH and Ft4 is completely inadequate, but all NHS will do

Once a year pay for full thyroid and vitamin testing privately

Any interim testing…..TSH, Ft4 and ft3….Monitor My Health is cheapest at £26.10 (NHS private test service)

Some of us find splitting levothyroxine dose into two smaller doses waking and bedtime helps improve conversion and might increase TSH a little

[Souzy in reply to SlowDragon]

Thanks again SlowDragon

I'm not on any medication for thyroid issues though (just for low potassium since June 2021 and high blood pressure since March 2022)

I've always been in range for TSH and T4 and only realised I might have Hashimotos from reading up on it on the internet which led me to this website.

[SlowDragon Administrator in reply to Souzy]

Sorry….. yes …. Not on Levothyroxine (yet)

Be interesting to see if gluten free diet gives improvement

[Souzy in reply to SlowDragon]

I'll keep you posted 🙂