why does our thyroid suddenly become less effective?

[BrocksfieldJo]

I was almost 54 when a blood test told me I had a less effective thyroid and since this time last year I’ve gone from 50mcg to 75 and now up to 100 to see if it can get to the right level. I’ve been a serial dieter for 30 years and have blamed this. My Father had a goitre most of his adult life that became a cancer at 80 and invaded his larynx. I know this runs in families, my daughter has Levo too now. Do we know why this happens? Just after some further info really. The dieting has stopped and I’m learning to be happy in my larger self!!

[SlowDragon Administrator]

Levothyroxine doesn’t “top up” your failing thyroid….it replaces it

Almost everyone will end up on full replacement dose when adequately treated

Typically that’s approximately 1.6mcg Levo per kilo of your weight

Even if we frequently start on only 50mcg, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

pathlabs.rlbuht.nhs.uk/tft_...

Guiding Treatment with Thyroxine:

In the majority of patients 50-100 μg thyroxine can be used as the starting dose. Alterations in dose are achieved by using 25-50 μg increments and adequacy of the new dose can be confirmed by repeat measurement of TSH after 2-3 months.

The majority of patients will be clinically euthyroid with a ‘normal’ TSH and having thyroxine replacement in the range 75-150 μg/day (1.6ug/Kg on average).

The recommended approach is to titrate thyroxine therapy against the TSH concentration whilst assessing clinical well-being. The target is a serum TSH within the reference range.

……The primary target of thyroxine replacement therapy is to make the patient feel well and to achieve a serum TSH that is within the reference range. The corresponding FT4 will be within or slightly above its reference range.

The minimum period to achieve stable concentrations after a change in dose of thyroxine is two months and thyroid function tests should not normally be requested before this period has elapsed.

NICE guidelines on full replacement dose

nice.org.uk/guidance/ng145/...

1.3.6

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here

cks.nice.org.uk/topics/hypo...

presumably you have autoimmune thyroid disease aka Hashimoto’s

Bloods should be retested 6-8 weeks after each dose change or brand change in levothyroxine

For full Thyroid evaluation you need TSH, FT4 and FT3 tested

Also both TPO and TG thyroid antibodies tested at least once for Hashimoto’s

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

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)

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

Testing options and includes money off codes for private testing

thyroiduk.org/testing/

Medichecks Thyroid plus antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

Only do private testing early Monday or Tuesday morning.

Link about thyroid blood tests

thyroiduk.org/testing/thyro...

Link about Hashimoto’s

thyroiduk.org/hypothyroid-b...

Symptoms of hypothyroidism

thyroiduk.org/signs-and-sym...

Tips on how to do DIY finger prick test

support.medichecks.com/hc/e...

Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee

[BrocksfieldJo in reply to SlowDragon]

the Dr always refers to it as underactive thyroid which is contradictory really 🤷🏻‍♀️ I am overweight which might be why my dose is being gradually increased but when I ask why they never give me an answer! Frustrating. Nobody has mentioned Hashimoto to me either. Just assumed I’d messed up my metabolism through the endless diet binge cycle I’ve been on.

[SlowDragon Administrator in reply to BrocksfieldJo]

First step

Get FULL thyroid and vitamin testing

See exactly what is going on

Important to test with correct timing

Assuming you have autoimmune thyroid disease, it’s frequently extremely beneficial to be on strictly gluten free diet

GP should do coeliac blood test first BEFORE you trial cutting gluten out