T4 and T3 blood results. How do I know if I am ... - Thyroid UK

Thyroid UK

141,188 members166,426 posts

T4 and T3 blood results. How do I know if I am converting properly?

Mouse profile image
5 Replies

I have just had my latest blood results and I think I remember someone talking about the ratio of T4 to T3 to tell if you are converting properly.

Have I remember this correctly and if so do my results show that I am or not?

TSH 2.1 (0.2-5.5)

T4 13.1 (10.0-24.5)

T3 5.0 (3.9-6.7)

These were taken at 3.40pm as I couldn't get an earlier appointment

Written by
Mouse profile image
Mouse
To view profiles and participate in discussions please or .
Read more about...
5 Replies
greygoose profile image
greygoose

I would say they don't suggest a convertion problem but a need for an increase in meds. Neither the T4 nor the T3 are even mid-range, which is much too low for you to feel well. Also your TSH is too high.

However, given that the test was done so late in the day, the TSH would have been even higher at eight o'clock, but I don't know what effect that would have had on the frees. Possibly they would have been even lower. Even so, you need an increase.

Hugs, Grey

Clarebear profile image
Clarebear

I think I remember from a post Rod made, that ft3 and ft4 are at their lowest in the late afternoon.

I too think that you need an increase in T4. Your next blood test will then be very interesting to see xx

nobodysdriving profile image
nobodysdriving

yup, increase :)

marram profile image
marram

Mouse. Your ratio of T4:T3 is better than 3:1 which is not bad at all, no signs of conversion problem, unless when you get an increase you did not feel any better.

I agree though that they both look low so an increase would be good. Your T3 is close to OK but it all depends how you feel, of course. That is the no1 consideration.

(Just for comparison, my T4 is 24.6 (range 12-22) and my T3 is 4.5 (range 3.1 - 6.8) so my ratio is about 5.5:1 which is not a particularly good conversion rate.)

Marie XX

Mouse profile image
Mouse in reply tomarram

Thank you for this information.

I cannot increase my dose as it makes me feel worse but I think I may have a problem with my adrenals. I did a saliva test about a year ago when it was OK but I have just had Scarlet fever and since then I have had a lot of adrenal symptoms.

I have an appointment with Dr Peatfield but it is not until August.

Not what you're looking for?

You may also like...

Am I converting T4 to T3 adequately?

Do I need T3 now? I'm currently taking 100mcg Levo and have felt so normal for around 9 months...
msmono profile image

Am I converting T4 to T3?

I still have terrible fatigue and can't lose weight, even though I diet and exercise every day. My...
Mitsy123 profile image

T4 & T3 levels and whether I am not converting to T3

Hello Everyone. I am looking for a bit of advice. I have been on T4 Levothyroxine for around 5...
lynnie0123 profile image

How to tell if converting well from t4 to t3

What does one look for in blood lab test results to tell if proper conversion is taking place from...
Meadowsmom profile image

Blood Results T4/T3

My GP just checked my bloods (interestingly she said the lab would only check my T4 if my TSH was...
SassyMH profile image

Moderation team

See all
Buddy195 profile image
Buddy195Administrator
RedApple profile image
RedAppleAdministrator
PurpleNails profile image
PurpleNailsAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.