Low TSH but normal Ft4 & Ft3

[Lib_Scot]

Hi Folks

Advice please - Just been informed that my recent thyroid tests from endo, would anyone thrown some light what this means. The letter basically says normal ft3 & ft4 levels but TSH is 0.1 to redo bloods in 3 months.

TSH - 0.1 m U/L (0.4 - 4.0) - May 2024

Ft4 - 18.4 pool/l (11.5 - 22.7) - May 2024

(My previous Ft3 was 4.9 pool/L (3.3 - 6.1) - Oct 2023

Letter says that Ft3 is normal

I’ve been hypothyroid for a couple of decades

I take 100mcg daily of thyroxine - will this need increasing?

Thank you

[Buddy195 Administrator]

Can you supply the ranges for your test results, as these can vary between laboratories (in brackets after results)?

When GPs say normal/ within range, this may not be the same as optimal, so always ask for a print out of your results.

Have you tested key thyroid vitamin levels: folate, ferritin, B12 and vit D? Having these optimal supports thyroid health.

[Lib_Scot in reply to Buddy195]

Hi

Thanks for responding

I’ve updated my post to include ranges and ft3 results from previous bloods done in Oct 2023

Yes, have been tested for the irons and are all normal- I have pernicious anaemia so get b12 every 10 weeks / I take ferrous fumerate due to past anaemia and take Vit D just as a maintenance dose

[SlowDragon Administrator]

looking at your previous post you are a complex patient

healthunlocked.com/thyroidu...

Essential to test vitamin D, folate and ferritin

TSH, Ft4 and Ft3

Do you always get same brand levothyroxine at each prescription

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

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

[Lib_Scot]

Yes, I am complex - very auto immune

Thyroxine brand - it can switch between 2 brands. It’s a case of whatever the chemist can get the cheapest which is not ideal

I will bear that in mind when I go for testing the next in 3 months

Thanks

[Buddy195 Administrator]

If you tolerate certain brands better than others, ask your GP to write these specifically on your prescription.

[Lib_Scot in reply to Buddy195]

Ok, good to know. There is one brand I prefer over the other 👍