It's true, you don't convert very well, but on the other hand, you're under-medicated. Your FT3 is much, much too low, but your FT4 isn't very high, either, not even mid-range. You need an increase in dose - or was it after this test that you increased to 125?
And, you have Hashi's? Do you know much about Hashi's?
The nurse practitioner knows nothing about thyroid. TSH is irrelevant once you are on thyroid hormone replacement, unless it goes high. Going low does not mean you're over-medicated unless your FT3 is over-range. And yours is scraping along the bottom. Reduce your dose and it will go under-range. Yes, I think some T3 would do you the world of good!
I see so many results like these on the forums. Your TSH is far too low for someone with a slightly below average fT4 and a low fT3. TSH stimulates type-2 deiodinase (D2) which converts T4 to T3. This has been demonstrated in the thyroid and in brown adipose tissue, I also believe it applies to D2 in the brain but there is no research evidence available. As long as your pituitary fails to produce sufficient TSH you will have impaired D2, which is the main form of T4 to T3 conversion. This also means in your case TSH cannot be used as a marker for thyroid hormone status because it is inappropriately low. When TSH is very low it causes 'secondary hypothyroidism' which arises from a pituitary problem. I wouldn't categorise your case as secondary hypothyroidism as it is less severe and I think it is very unlikely you have a damaged pituitary. This form of low TSH can be caused by severe dieting, depression or a period of thyrotoxicity which can occur in autoimmune hypothyroidism and may not be noticed. The hypothalamic pituitary thyroid axis gets down-regulated.
Since you are not secreting sufficient TSH you will have imparied D2 and will require some T3, perhaps around 20 mcg liothyronine, more than is usually secreted by the thyroid. If your endocrinologist wants to increase your levothyroxine then by all means give it a try but I suspect it will not work. Eventually as your fT4 approaches and exceeds the upper limit of its reference interval (21) you will find fT3 starts to rise but this is due to type-1 deiodinase (D1). D1 acts as a mechanism to prevent excess hormone, it coverts T4 to T3 but also converts T4 to reverse T3 (rT3). rT3 inhibits the action of T3.
greygoose it is completely wrong to say that TSH is irrelevant when on thyroid hormone replacement. TSH is equally relevant whether or not the patient is on hormone supplementation, the same feedback mechanisms apply. A patient can be over-medicated with an fT3 within its reference interval. Most patients will be appropriately medicated when their fT3 is around mid-interval. Obviously in this case TSH is not relevant. Also it is likely that AussieInNorfolk will need higher fT3 levels to overcome symptoms, for complex reasons to do with deiodinase. These higher fT3 levels do carry some cardiac and bone risks but there's not much choice if s/he wants to get better and have a normal life.
Thank you for letting me know you were talking about me so that I can put my point of view! Most courteous of you.
You just said yourself that "This also means in your case TSH cannot be used as a marker for thyroid hormone status because it is inappropriately low." And, from what I've seen, this applies to most hypos. Doctors/nurses should not be dosing by the TSH. End of. How many practitioners do you think know anything about type-2 deiodinase? Very, very few. They just see a low TSH and automatically reduce the dose. And that is wrong - especially in a case like this. And, as you said yourself we "see so many results like these on the forums." meaning that the TSH is totally unreliable in hypos. So, to all intents and purposes - and as far as the knowledge of the majority of doctors is concerned - the TSH is irrelevant for hypos unless it goes high - that, at least, does give them a clue that the dose is to low. Well, some of them, anyway. When doctors are better educated, TSH might be of some use to them, but with their normal sledge-hammer approach to hypo treatment, it's of no use at all!
Oh, and by the way, I meant TSH the test, not TSH the hormone, if that's what confused you.
I agree TSH is a very poor marker for thyroid hormone activity. I don't know of any study that shows a good correlation between TSH and clinical response. Whilst it is a good specific marker for primary hypothyroidism (if TSH is high, above 10.0, almost certainly the thyroid is failing), it is not a sensitive marker, many hypothyroid patients do not have an elevated TSH.
TSH can be useful. We know that a suppressed TSH is associated with osteoporosis and atrial fibrillation. Therefore if we need to suppress TSH we should take extra care. More importantly we know that TSH should be elevated if fT3 and fT4 are low. This applies to AussieInNorfolk, her TSH should not be so low as she has low thyroid hormone levels. An added complication is that when the pituitary fails to produce sufficient TSH the isoforms of TSH it produces have reduced bioactivity. The TSH assay measures the presence of TSH and not its potency.
So we should pay attention to TSH but it requires skilled interpretation which is generally not available from GPs or endocrinologists!
Many researchers have found that a combination of T4/T3 suits many people and need T3 added to T4 or T3 alone.
The medical profession seem to be the last people on earth to be able to support hypothyroid patients to good health as they restrict their doses in order to keep numbers 'somewhere in the range' when all numbers should be optimal i.e. TSH 1 or lower, Free T4 and free T3 optimal. Few test FT4 and FT3.
You need a higher dose to bring FT4 and FT3 towards the upper part of the range.
Do you know that blood tests have to be at the earliest possible, fasting (you can drink water) and allow a gap of 24 hours between last dose and test and take afterwards. This help keeps the TSH at its highest as it drops throughout the day and may make a difference between getting an increase or a reduction in dose.
I am suffering with the same symptoms you mentioned here! Severely dry eyes, sore joints, exhaustion! I was beginning to think it might be Sjogrens but it sounds like it's due to undermedicating going by the posts above?
I'm currently trailing T3 and trying to up the dose to see if I feel better 😊
As you have Hashimoto's low vitamins are extremely likely
Essential to test vitamin D, folate, ferritin and B12. Always get actual results and ranges. Post results when you have them, members can advise
What supplements are you taking, if any?
Are you already on strictly gluten free diet?
Hashimoto's affects the gut and leads to low stomach acid and then low vitamin levels. Low vitamin levels can 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)
Changing to a strictly gluten free diet may help reduce symptoms, help gut heal and slowly lower TPO antibodies
Your FT4 is no where near top of the range so as greygoose says, you likely have room for dose increase.
But GP will be extremely unlikely to agree
Getting vitamins optimal is essential before considering adding small dose of T3 and also trying strictly gluten free diet likely to help
Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.
In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.
Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.
This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."
You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor please email Dionne at
tukadmin@thyroiduk.org
Plus suggest you request list of recommended thyroid specialists. Some are T3 friendly
Professor Toft recent article saying, T3 may be necessary for many
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)
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