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Thyroid UK
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Underactive thyroid

I was diagnosed with an underactive thyroid in March with antibodies 589.

I have recently just had my bloods done again but am unable to understand them as no one has took the time to help me understand them. I was on 100mg levothroxine until about three weeks ago and my bloods came back today as:

Serum free T4 11.0 (12.0-22.0)

Serum TSH level 4.72 (0.3-4.5)

I suppose im just struggling to understand how one is high and one is low?

Would someone also be able to explain what free T4 and TSH levels are and what they are for?

When my thyroid antibodies were done in March they were 589.

Can my thyroid rightify itself?

10 Replies

Last question first : no, your thyroid cannot rightify itself.

You have high antibodies, so you have Hashimoto's Thyroiditis - aka Autoimmune Thyroiditis - where your immune system attacks the thyroid and slowly destroys it. There is no cure for Hashi's, but you can try to reduce the antibodies by adopting a 100% gluten-free diet and taking selenium.

TSH is a pituitary hormone. Thyroid Stimulating Hormone. When the pituitary - a small gland in the brain - senses that there is not enough hormone in the blood, it secrets TSH to stimulate the thyroid to make more hormone. If, for some reason, the thyroid cannot respond, the TSH continues to rise. Your thyroid cannot respond because it has been damaged by your immune system. Therefore, you have to take thyroid hormone replacement - levo, NDT, T3 - to replace those hormones, to keep you alive. You cannot live without thyroid hormone.

FT4 - Free T4 - is a thyroid hormone (levo) and as the level rises, the TSH decreases. That is why your TSH is high, it's because your FT4 is low.

Your high TSH and low FT4 are saying that your dose of levo is too low, and you need an increase. Your TSH needs to come down to around 1, and your FT4 needs to rise to at least over mid-range for you to feel better. :)

1 like

Thankyou for your reply.

What is selenium?

If I was to adopt a gluten free diet would my antibodies return to normal?


Many of us with Hashimoto's do find TPO antibodies fall very slowly after going strictly gluten free as gut heals. It's not a quick fix for the actual TPO numbers, but it can for many make noticeable improvements in symptoms, sometimes pretty quickly, others it's more of slow subtle improvements

Selenium is a mineral supplement.

Generally recommended, especially with Hashimoto's.

Lots of different makes available.

Everyone has their own favourite no doubt. Personally I take Solgar vitamin E with selenium.


I like Selenium Methionine from epigenetics-international.com


An easy read re the throid:selenium connection chriskresser.com/selenium-t...


That's not a question anybody can answer with any certitude. But, even if they did return to normal levels, you would still have Hashi's. Antibodies are not the disease, they are the result of the disease. They come in after an immune attack to clean up the 'mess'. Which is why they fluctuate - high just after an attack, then receding until the next attack. But, they themselves don't do the attacking.

The thing is, a lot of people find that the antibodies themselves cause some symptoms, independent of hormone levels. Therefore, reducing them makes people feel better. And being gluten-free will also help your gut to heal. And, selenium will support also support conversion.


I always learn so much when I read your posts Greygoose (along with other valued commentators). Please keep them coming.


Thank you, Adam. :)


For full evaluation blood tests should include TSH, FT4, FT3, TT4 plus vitamin D, folate, ferritin and B12

All thyroid tests should be done as early as possible in morning and fasting and don't take Levo in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results

Link about antibodies


Link about thyroid blood tests


You are under medicated to gave a TSH so high and need 25mcg dose increase. Blood should be retested 6-8 weeks and every dose increase. Dose increased until TSH is around one and FT4 towards top of range and FT3 at least half way in range

Print this list of symptoms off, tick all that apply and take to GP


As Greygoose says, your high antibodies confirm you have Hashimoto's

Hashimoto's affects the gut and leads to low stomach acid and then low vitamin levels

Low vitamin levels affect Thyroid hormone working

Poor gut function can lead leaky gut (literally holes in gut wall) this can cause food intolerances. Most common by far is gluten

According to Izabella Wentz the Thyroid Pharmacist approx 5% with Hashimoto's are coeliac, but over 80% find gluten free diet helps significantly. Either due to direct gluten intolerance (no test available) or due to leaky gut and gluten causing molecular mimicry (see Amy Myers link)

But don't be surprised that GP or endo never mention gut, gluten or low vitamins. Hashimoto's is very poorly understood

Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies

Ask GP for coeliac blood test first







1 like

I will request a copy of my blood results and post 2moro.

Thanks for the links I will have a read through


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