New Blood Results: Hi all. With raising my... - Thyroid UK

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New Blood Results


Hi all. With raising my levothyroxine dose from 75 to 100, by alternating dosage, I have managed to cope with most of the symptoms. Still flushing/sweating and pulse rate is a bit over sometimes, weight gain, etc. But I wanted to see if the increase was helping and these are my new results. It seems to be a lot better and I don't think there is a conversion problem, is that right?

Any help greatly appreciated. Thank you

Thyroid Function


FREE THYROXINE 21 pmol/L 12.00 - 22.00

FREE T3 4.47 pmol/L 3.10 - 6.80

20 Replies

Oh, I think there is a conversion problem. Your FT4 is right up the top and your FT3 is just under mid-range. There shouldn't be such a wide gap.

Hidden in reply to greygoose

Thank you greygoose

greygoose in reply to Hidden

You're welcome. :)

These results are good, more or less optimal for levothyroxine therapy with fT3 around mid-interval. Good numbers doesn't always lead to good health. Conversion is a difficult issue. There are two types of T4 to T3 conversion. D1 which converts T4 to T3 and to reverse T3 (which blocks the action of T3) and D2 which converts T4 to T3. D2 increases when fT3 is low whereas D1 increases when fT4 goes high. If you take more levothyroxine you will see your fT3 figure jump up but you won't feel any better because reverse T3 will jump up also. D1 seems to be a mechanism for mitigating hyperthyroidism. In healthy people the body tries to keep fT3 around mid-interval, a little lower if fT4 is a little high and vice-versa.

Can you give us an idea of your symptoms, what is causing you problems? Sweating, high pulse suggests too much hormone, weight gain could be hypo or something else. What other symptoms do you have?

Hidden in reply to jimh111

Hi jimh and thank you for your reply.

I have Hashimotos. The increase in dose has helped ease some symptoms but the ones I’m left with seem to get worse on increase. Anxiety/irritability- Sweating/flushing - Fatigue/no energy - Brain fog - Weight gain, and occasionally my pulse seems to race. Seems my body temperature and metabolism have ceased to work anymore 😞

jimh111 in reply to Hidden

This is so difficult. Anxiety is a symptom of hyper whereas I used to get irritable when hypo. Sweating is hyper, fatigue can be hypo or hyper, brain fog & weight gain hypo. I assume you get these symptoms most of the time? With Hashimoto's you can get thyroid flare ups, be hypo for a few weeks and then hyper. I don't think this is happening to you as your blood test results are a bit textbook, flare ups tend to give occasional high fT3 figures.

I would supplement with magnesium as most people are deficient, especially in hypothroidism. Magnesium oxide is useless, I like magnesium citrate but others will recommend different forms which are also OK. Magnesium blood tests do not tell you anything as it is the intracellular levels that matter and there is no blood test for this.

I'm not sure what to do with your thyroid hormones. I wouldn't increase your levothyroxine as your fT4 will go too high and you will produce rT3 which is counter productive. Your fT4 is reasonably high on 75 / 100 mcg levothyroxine which suggests your thyroid is still producing some hormone. I would try to avoid suppressing your TSH as this can lead to a 'down regulated axis', your TSH becomes permantly low as a result of suppressing it for some time. In the long term if you can only get better by suppressing your TSH then we have to accept this but it is better to try and avoid it. Depending on how your current symptoms are affecting your life I'd be temped to stay as you are for a few months to see if you improve, it does take time to recover from hypothyroidism.

Hidden in reply to jimh111

Thanks for all the info jimh, that’s very interesting.

FancyPants54 in reply to Hidden

I get terrible anxiety with too much medication for my body to cope with, and with hypo. Too little or too much is the same where anxiety is concerned for me.

Ldhorsey in reply to jimh111

I didn’t realize with Hashimotos the thyroid could be hyper and hypo. This could explain why my mood takes a dump big time seems like about once a month. I seem to get depressed and have mild panic attacks for a couple of days and then it’s gone and I wonder what that was all about.

blue horizon do a red cell magnesium blood test that gives you must better info than a serum magnesium. But most people just supplement and go by how they feel. Medichecks also do it, perhaps others do too.

moomoo17 in reply to moomoo17

also make sure vit d, folate, ferritin, b12, bone profile zinc and selenium if you can, some people just take zinc and selenium but I preferred having a baseline to dose from, b6 could be useful to test, fbc if the Dr hasn't already done one.

jimh111 in reply to moomoo17

rbc magnesium is a little better than serum Mg but still not much use because it measures the total Mg in red blood cells as opposed to free magnesium in other tissues. The 'gold standard' test for magnesium is the 'magnesium loading test' which measures Mg retention before and after supplementation for a period of time. This is only useful in research. From our point of view the best approach is to simply eat magnesium rich foods (and water) and supplement to see if it makes a difference.

moomoo17 in reply to jimh111

hi jim, thank you for your reply, its really helpful. I knew there is an iodine loading test so thats interesting there's also a magnesium. I agree with you there re supplementing, thats exactly what I said in my reply. I definitely find magnesium glycinate and malate combination isbest for me, I take it to support my vit d supplements too.


I see from your other posts you have Hashimoto's and have had low vitamins in the past

What vitamins are you supplementing now if any?

Have you had vitamin D, folate, ferritin and B12 retested recently?

As you have Hashimoto's are you on strictly gluten free diet? Very many find it helps significantly

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. Dairy is second most common.

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)

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

Ideally ask GP for coeliac blood test first

I e always been told FT4 and FT3 should be both in the top third or even the top quarter of their respective ranges. As GG has said yours aren't. You have taken supplementsxin the past. Are you still taking them as once low we will always be low if we stop them. I thing Vit D particularly falls like a brick! You may though, once you are back on track experiment to so if you can find a maintenance dose that suits you.

jimh111 in reply to silverfox7

It's wrong to say fT3 and fT4 'should' be in the upper third or wherever. Healthy people have fT3 and fT4 within their reference intervals and they tend to alternate with one higher than the other (otherwise if both were high TSH would go low, or if both low TSH would go high). For patients treated with levothyroxine fT3 tends to achieve normal levels when fT4 is high in interval. This seems a reasonable initial taget, to get back to normal fT3 levels.

Some people do need higher fT3, fT4 levels sometimes very high but it's not a good idea to set the upper thirds as general targets. So, whilst many patients on the forums do need slightly higher fT3, fT4 levels it's not a good idea to set these as targets.

How did you get the rest done? My GP refused all but T4 and TPO

SlowDragonAdministrator in reply to janm3309

Do you have high TPO antibodies?

I see on your other post you have gluten intolerance.

Ask GP to test vitamin D, folate, ferritin and B12

Low vitamins are common when hypo and especially with Hashimoto's which often causes gluten intolerance

For full Thyroid evaluation you really need TSH, FT4, TT4, FT3 plus TPO and TG thyroid antibodies. Plus vitamin D, folate, ferritin and B12.

Essential to test thyroid antibodies, FT3 and FT4, plus vitamins

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should ideally be done as early as possible in morning and fasting.

If on Levothyroxine, don't take in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, GP will be unaware)

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).

About 90% of all hypothyroidism in Uk is due to Hashimoto's. Low vitamins are especially common with Hashimoto's. Food intolerances too, especially gluten. So it's important to get tested.

I have hashimotos. My anxiety and fatigue greatly reduced / disappeared when I started supplementing with Vitamin D and Iron. Please get these and B12 tested. Good Luck.


Thanks to everyone who posted. So many useful and interesting points!

I should of mentioned I am gluten free, and I have been tested for Vit D, B12, Follate and Ferritin. Also Magnesium and Potassium. All tests came back ok, except Vit D was low and Iron was borderline. So taking supplements of those.

The Endocrinologist wants to do more tests, Cortisol and Oestrogen? and will mean going on a ward where my bloods will be monitored every hour. I have unusually high levels of Oestrogen.

If all tests come back fine, he said we could trial T3, but my Gp will have to prescribe it 🙄

When I get results back, I will post them here.

Once again, thank you all for the great info.

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