Your antibodies don't suggest autoimmune thyroid disease, I don't think anybody has zero antibodies. I don't have Hashi's and my antibodies have always been around 6-12ish for TPO and 11-20ish for Tg.
I am not medically trained, and I am not diagnosing, but what could be indicated here is Central Hypothyroidism. This is where the problem lies with the hypothalamus or the pituitary rather than a problem with the thyroid gland. With Central Hypothyroidism the TSH can be low, normal or slightly raised, and the FT4 will be low/below range.
TSH is a pituitary hormone, the pituitary checks to see if there is enough thyroid hormone, if not it sends a message to the thyroid to produce some. That message is TSH (Thyroid Stimulating Hormone). In Primary Hypothyroidism the TSH will be high. If there is enough hormone then there's no need for the pituitary to send the message to the thyroid so TSH remains low.
However, with Central Hypothyroidism the signal isn't getting through for whatever reason. It could be due to a problem with the pituitary (Secondary Hypothyroidism) or the hypothalamus (Tertiary Hypothyroidism).
As Central Hypothyroidism isn't as common as Primary Hypothyroidism it's likely that your GP hasn't come across it before.
Your GP can look at BMJ Best Practice for information - here is something you can read without needing to be subscribed:
You could do some more research, print out anything that may help and show your GP.
You may need to be referred to an endocrinologist. If so then please make absolutely sure that it is a thyroid specialist that you see. Most endos are diabetes specialists and know little about the thyroid gland (they like to think they do and very often end up making us much more unwell that we were before seeing them). You can email Dionne at
tukadmin@thyroiduk.org
for the list of thyroid friendly endos. Then ask on the forum for feedback on any that you can get to. Then if your GP refers you, make sure it is to one recommended here. It's no guarantee that they will understand Central Hypothyroidism but it's better than seeing a diabetes specialist. You could also ask on the forum if anyone has been successful in getting a diagnosis of Central Hypothyroidism, possibly in your area which you'll have to mention of course.
Thanks for the replies - very helpful as ever. I will need to contact my doctor with the updated results and try and get a ultrasound and endo referral. If he will not help out then I will have to go private for ultrasound and initial consultation and then take the results back to the doctor. Like you have both said it is looking most likely like Central Hypothyroidism - I just need the ultrasound to rule out Hashimotos. Apparently about 40% of Central Hypothyroidism patients have a benign tumor on the pituitary - not sure if that is correct.
I have also emailed for the list of endocrinologists.
thanks for all the help - hopefully I am finally getting somewhere
Well the GP was not particularly helpful.Here is his response "I would have assessed those results as essentially normal and not indicative of significant thyroid disease or dysfunction as the TSH is in the middle of the normal range and is the most important indicator of thyroid status. The T4 is only marginally outside the normal range and is quite a labile value in normal individuals, hence TSH being the mainstay of thyroid monitoring. The T3 is normal as are the thyroid antibody titres. Lack of raised antibodies would point away from Hashimotos."Not sure what to do now.
Did you give him/send him the evidence about Central Hypothyroidism? Did you read it yourself so you were prepared for the conversation? He probably hasn't heard of it, and your below range FT4 is THE most important result where this is concerned so you have to emphasise this.
TSH is important for diagnosis of Primary Hypothyroidism but it isn't where Central Hypothyroidism is concerned because the feedback loop is broken. Due to the pituitary not responding to low levels of thyroid hormone (where TSH would normally rise in Primary Hypothyroidism) the TSH doesn't rise in Central Hypothyroidism so it's the below range FT4 that is the clue.
Hi - yes the consultation was all online due to Covid etc. I sent over all the links etc that you sent me so I presume he must have looked at them.He replied saying "'Central Hypothyroidism' I presume refers to hypothalamic/pituitary insufficiency causing a reduced capacity for the hypothalamus and pituitary areas in the brain to produce TRH and TSH which then goes on to drive the thyroid production of T3 and T4. Your TSH is normal, but if it were the case that you have borderline hypothalamic/pituitary insufficiency then it is generally not selective and one might expect other control hormones produced there to be lower than expected, so potentially if we can recheck the T4 and TSH (standard thyroid profile) we could add LH and FSH to that. Investigating further than that if you are still concerned would be beyond our remit in Primary Care"
My testosterone and cortisol are low so it seems other control hormones are affected?. I have not had LH tested previously.
I am booked in to get the blood test next week so hopefully the result of that will mean he has to refer me to an endocrinologist - although there may be a long waiting list.
I did actually find an online pharmacy based in the UK that can supply Levothyroxine. I am tempted to bypass the doctors and maybe start self medicating and monitor the results?
" T4 ......is quite a labile value in normal individuals, hence TSH being the mainstay of thyroid monitoring"
TSH is also labile , it goes up and down within each day meaning less people get diagnosed with hypothyroidism if they are tested in the afternoon, and it goes up and down related to the time in the menstrual cycle. So T4 being 'labile' is no reason to discount it.
And if central hypo is the problem TSH is totally unreliable .. the below range T4 is suggestive of this so he should follow up on the possibility of central hypo.
Central hypo is not restricted to just cases where TSH is 'below range'. it can also be present when TSH is 'normal'.... There is a link somewhere for a statement to this effect but i don't have it sorry.
A possible reason for T3 increasing, is that the increasing TSH has prompted better T4 to T3 conversion (and more T3 production from the thyroid) .. in an attempt to compensate for the falling T4 levels. This is an due to the action of TSH on the deiodinases that regulate T4/T3 balance.
Yes and my T4 was low on previous blood tests over the last 3 years. It has actually gotten worse and the tests were taken at different times of day etc. I would say having T4 being low on all tests is a reliable evidence of a problem. Also the Doctor seems to be ignoring that TSH is not reliable when looking at people with Central Hypothyroidism.thanks for your help.
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