Does low free thyroxine mean you are hypothyroid?

Hi

I’m looking at my lab results and my TSH is normal at 2.4 (.45-4.50) but my free t4 .81 (.82-1.767) was flagged as low as well as my T3 uptake 20 (24-39). My free t3 was 3.6 (2.0-4.4) and my free thyroxine index was 1.4 (1.2-4.9). Test was done at 8 am after fasting. Does this look like early hypothyroidism? My thyroid antibodies are negative so I’m just confused and was hoping for some insight.

[jimh111]

The numbers look OK as fT3 is good and fT4 just slightly below its lower limit (2.5% will be). Why do you suspect thyroid? What are your symptoms?

[SlowDragon Administrator]

Possibly

Could be low vitamin levels affecting thyroid

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially if you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies

Ask GP to test vitamin levels

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

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

Private tests are available as NHS currently rarely tests Ft3 or thyroid antibodies or all relevant vitamins

List of private testing options

thyroiduk.org/getting-a-dia...

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Thriva Thyroid plus antibodies and vitamins By DIY fingerpick test

thriva.co/tests/thyroid-test

Thriva also offer just vitamin testing

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test

bluehorizonbloodtests.co.uk...

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code

thyroiduk.org/getting-a-dia...

monitormyhealth.org.uk/

NHS easy postal kit vitamin D test £29 via

vitamindtest.org.uk

If TPO or TG thyroid antibodies are high this is usually due to Hashimoto’s (commonly known in UK as autoimmune thyroid disease).

About 90% of all primary hypothyroidism in Uk is due to Hashimoto’s. Low vitamin levels are particularly common with Hashimoto’s. Gluten intolerance is often a hidden issue to.

Link about thyroid blood tests

thyroiduk.org/getting-a-dia...

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

List of hypothyroid symptoms

thyroiduk.org/if-you-are-un...

Have you had BOTH TPO and TG antibodies tested?

Ultrasound scan of thyroid can be helpful

20% of Hashimoto's patients never have raised antibodies

healthunlocked.com/thyroidu...

Paul Robson on atrophied thyroid - especially if no TPO antibodies

paulrobinsonthyroid.com/cou...