Blood results...help, please

[Bearo]

I’ve been on Levo for almost a year. Currently on 75mcg. I have two previous TSH, T4 results but this is my first result adding T3.

Jan 2021

TSH 0.14

FT4. 15.9 (12-22) 39% through range

FT3. 4.6 (3.1-6.8) 40.5% through range

As my T3 is higher than T4 does this mean I convert well?

As neither is high in range, do I need an increase? I feel that I do. I’ve only felt better on Levo for the first five days of my increase to 75mcg.

Is my low TSH going to scupper getting that increase? My summary from Monitor My Health described me as sub clinical hyperthyroid, no need to medicate.

This was a 9am fasting blood test, biotin stopped beforehand.

I supplement 5,000 vit D. Oct - 92nmol

Igennus B complex

B12 500 or 1000 daily. Oct - 348ng/L

Magnesium

Folate. Oct - 14.6

Ferritin. Oct - 72

All comments gratefully received!

[SeasideSusie Remembering]

Bearo

As my T3 is higher than T4 does this mean I convert well?

Your FT4 and FT3 are nicely balanced, you convert well but they are quite low in range. The aim of a treated hypo patient on Levo only, generally, is for TSH to be 1 or lower with FT4 and FT3 in the upper part of their ranges if that is where you feel well. You would probably benefit from an increase in your dose of Levo.

Is my low TSH going to scupper getting that increase?

Possibly depending on your GP. Many GPs only dose by TSH, you will need to remind your GP that it is the FT4 and FT3 that are the thyroid hormones and the TSH is a signal from the pituitary. However be prepared for your GP to say that your FT4 and FT3 are in range so not a problem. However, you can refer to Dr Toft article in a 2010 issue of Pulse Magazine which stated:

“The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range – 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This ‘exogenous subclinical hyperthyroidism’ is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).”

You can email Dionne at ThyroidUK for a copy of the article and highlight question 6 to show your GP:

[e-mail]

[Bearo in reply to SeasideSusie]

Thanks

[Bearo in reply to SeasideSusie]

Actually I’m confused! How can TSH be 0.14? Doesn’t it go up to 0.9 then the next number is 1? My maths is very poor so please forgive what is probably a stupid question!

[SeasideSusie Remembering in reply to Bearo]

Bearo

How can TSH be 0.14? Doesn’t it go up to 0.9 then the next number is 1?

I understand it but may not explain it very well.

When you higher than 1 it is 1.1, 1.2, 1.3, 1.4, etc.

When you go lower than 1 it becomes 0.9, 0.8, 0.7, 0.6, etc. So 0.9 is a bit lower than 1 and 0.1 is a lot lower than 1 and 0.01 is even lower still.

Different machines are calibrated differently and some measure lower than others.

Many machines only measure as low as 0.02 so a result lower than that would be shown as <0.02 (with the symbol < meaning "lower than").

Some machines measure as low as 0.01.

Some go as low as 0.005

I don't know if that makes sense to you but all machines would be capable of measuring a level of 0.14

[Bearo in reply to SeasideSusie]

I followed until you said there can be a level of 0.14 and I still don’t understand that! But thank you for taking the time to reply!

[SeasideSusie Remembering in reply to Bearo]

Bearo

It's all down to decimals and how many decimal points you go to. Decimals are based on 10 numbers.

0.14 is just a bit higher than 0.1 it's just taking it to the next decimal place.

For example, between 0.1 and 0.2 there is

0.1

0. 11

0.12

0.13

0.14

0.15

0.16

0.17

0.18

0.19

0.2