I have had to repeat three of the last five Thyroid tests as they came back below TSH range. Had to speak to the Doctor who said the last one had come back lower and she thought I had subclinical hyperthyroiditis as my tests have been up and down since 2020, the last one was worse so it needed to be treated and was going to refer to the Consultant who may not want to see me but she needed some advice on how to manage it. I have received a letter now to say I am on the waiting list for an appointment. So I decided I needed to find out about the thyroid and i joined Thyroid UK. I filled in a form at the Doctors and got my results from 2020 but a lot of them are more general until the last couple. I am able to note some of them which might make some sense.
Serum TSH range (0.30-4.40)
17/09/20 0.19mu/L
25/03/21 0.32mu/L
02/12/21 0.31mu/L
11/08/22 0.25mu/L
04/01/23 0.16mu/L
Serum Free T4 Range (9-19.1)
17/09/20 16.3pmol/L
25/03/21 14.2pmol/L
02/12/21 15.5pmol/L
11/08/22 15.4pmol/L
04/01/23 15.5pmol/L
Serum C Reactive Protein <5
15/11/18 7mg/L
17/09/20 10mg/L
CRP was not tested any more.
I would appreciate your thoughts on these, there might be more results here which would help.
Ranges vary between lab, so always need to interpret results.
Ranges are usually shown in brackets after results. Can you add please.
Was any form of thyroid antibodies tested this might help see if anything autoimmune is occuring,
Sub clinic cal - hyperthyroid refer to below range TSH but thyroid levels being with in range (ie not symtomatic or in need of treatment)
Thyroiditis or “autoimmune thyroiditis” is where immune system attacks thyroid, this can have transient high level, but it is usually early on and the damage ultimately results in under active thyroid with high TSH & low FT4 & FT3.
FT3 is the active thyroid hormone and it doesn’t look like you have been tested which is wrong as you have low TSH but in range FT4.
I have a hyper nodule so I have low TSH - in range FT4 & high FT3. Which was missed for many years.
The ranges are there in brackets at the top of each test. Had to rewrite the post so might not be set out clearly or have all the information I had written before. No antibodies tested for or free T3 either but that might have to wait for the hospital. Also in 2011 after a long and hard time I was diagnosed with lupus.
Do you feel well ? or do you have any symptoms that could be caused by mild hyperthyroidism ?
Those TSH result are not 'worryingly' low.
'very low' would look like eg. 0.05 , or <0.001... Yours are only a bit under range , and that range which is a "95% population range" has already removed the 2.5% of the healthy population with the lowest TSH results, and the 2.5% with the highest ..meaning there are some healthy people whose 'normal (for them) is TSH slightly below that range .
So unless these TSH results are lower than what you 'normally' have , then it is possible that this is your 'normal' level of TSH . ( Do you by any chance have any TSH results from the years before these to compare them to ?)
TSH ( Thyroid Stimulating Hormone) is just a 'message' from the pituitary to the thyroid 'asking' it to make more or les thyroid hormones ( T4 and T3)
When T4 / or T3 levels are too high for the body the TSH goes very low.. (to stop 'asking' the thyroid for more T4/T3 to be made ... and when T4/T3 levels are too low ,the TSH rises to ask for more T4/T3 to be made .
High T4 and (more importantly High T3) are what actually cause symptoms of hypothyroidism. (TSH doesn't actually 'do' anything ).
Your T4 results are comfortably in range , and seem stable over those tests. so if you don't have any symptoms of hyperthyroidism. them it is possible this level of T4 is normal for you .
Knowing what your T3 Level is may be more enlightening , as T3 is the 'active' hormone (T4 is more of a 'storage' form which is converted into T3 inside your cells)
The fact that your TSH is lower on the last test may be an early sign of mild hyperthyroidism developing..( hence the GP asking endo to have a look at it and the GP keeping an eye on you )
....BUT it may not mean that..... it may simply be lower because the TSH test was taken at a different time of day to the previous ones .
TSH has circadian rhythm .TSH is higher in the early morning and falls to it's lowest around 1-3pm ish .. then rises slowly again to it's highest around midnight .
Can you remeber what time of day these TSH tests were taken ?
The tests were at the doctors all round about 10ish. no more results than that unless there are more on the computer at the doctors. Have never been referred or been treated. 12years ago after some years I was diagnosed with lupus so I put the times I felt unwell down to that, which is why I just accepted things
OK so if all done at similar time of day , it could be genuine trend of TSH lowering.. you'll have to 'watch and wait' i think ... see what happen to it next .
oh...just seen the lab range for last fT4 test ( did the lab range for the last TSH test change too ? )
When fT4 / fT3 tests are done using a different ref range , we can only compare them by converting the results to a "% through range" .
When you do that ...you can see that the last test shows your level of T4 has actually gone up a bit , which would explain the lower TSH on that last test.
11/08/22 fT4: 15.4 (9-19.1) 63.37%
04/01/23 fT4: 15.5 (8.9-17.3) 78.57%
( '% through range' calculator for comparing tests with different ranges thyroid.dopiaza.org/ )
It was only the fT4 that changed. I think your right about wait and see, or maybe looking at a private test to put me better in the picture as the wait might be a long one!
The blood tests done around 10 ish. Found vit B12 (130 - 900)02/12/21 218ng/L
11/08/22. 219ng/L
Ferritin (15-300)
02/12/21 43ug/L
11/08/22 60ug/7L
Folate>3
02/12/21 7.8ug/L
11/08/22 5.3ug/L
I take B Complex
Vitamin D - prescribed as levels were in my boots due to lupus about 16 years or so and told I would have to take them for life. Never been tested to my knowledge
Relying on TSH and FT4 will not give you an accurate analysis of your thyroid function.
The outcome is likely to be an inaccurate diagnosis followed by wrong medication which then causes health issues
We expect our medics to be clued up but regretfully they are not well trained re thyroid disease... they basically muddle along with the limited knowledge they have acquired... and their patients often accept the resulting poor quality of life as being their lot
Were it otherwise then over 130,000 patients would not have arrived here having been failed by their medics.
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