Links wanted for articles about the irrelevance... - Thyroid UK

Thyroid UK

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Links wanted for articles about the irrelevance of low TSH especially when taking T3 - also odd results!!


Hello following on from my previous post, I have a letter from my GP asking me to make an appointment, obviously because my TSH was so low. Does anyone have relevant links explaining that TSH is irrelevant (when taking T3 as well as T4) so she doesn't reduce my levothyroxine prescription.

My results were from a morning blood draw, having not yet taken my meds (100mc Levo plus 12.5 Cytomel) strange the hormones are so low and TSH also so low, my FT3 GP recording a year ago was higher at 4.00 pmol/L when I was only on Levo!!

Serum TSH level 0.01 mIU/L . ( 0.35 - 4.94 ) Abnormal

Serum free T4 level 12.20 pmol/L (9.01 - 19.05) normal

Serum free T3 level 3.60 pmol/L (2.63 - 5.70) . Normal

5 Replies

Your FT3 and FT4 are both low

What are your vitamin D, folate, ferritin and B12 levels like?

As you have Hashimoto's low vitamin levels are extremely common

Ask GP to test these if not been done in last 3 months

Are you on strictly gluten free diet?

If not ask for coeliac blood test

from STTM

TSH: The worst test to go by. Why? Because too many patients have found themselves with a good-looking TSH with raging hypothyroidism. By the time it rises high enough, you’ve been hypothyroid for a certain length of time. Better to diagnose and dose by is the free T3 and free T4, NOT the TSH.

Notes: We have noticed that the best way to use the TSH lab test is in diagnosing a pituitary problem, not a thyroid problem. A very low TSH with a low free T3 gives away a hypopituitary issue. We do know that healthy people tend to have a TSH in 1’s and not much higher. We also know that many with clearly hypothyroidism can have a “normal” result sadly which will take years to rise high enough to reveal one’s hypothyroidism. Otherwise, we honestly pay no attention to it.

Supposedly, it measures the actual TSH in your body, called the Thyroid Stimulating Hormone, a pituitary hormone messenger. Yup, they are using a pituitary hormone to tell you if you have a thyroid issue. For example, if your body needs more thyroid hormones, the pituitary gland releases the TSH in order to knock on the door of your thyroid to produce more hormones. So theoretically, the higher the TSH lab test, the more your body is screaming at your thyroid to produce! produce! Creators of the TSH lab test came up with a ‘range’ that supposedly corresponds with healthy thyroid function. So theoretically, if your TSH lab results are higher than the range, it would imply something is triggering your actual TSH to be a little too active in screaming at your thyroid. That something would be a diseased thyroid, called hypothyroid. But there are problems with this method of diagnosis. First, you can have a so-called normal result, yet be clearly hypothyroid with symptoms. Why? Because the TSH test cannot measure if all your cells & tissue are receiving the released thyroid hormones. Some may be (thus the normal TSH result) and some may not be (thus your clear symptoms). Second, if you have Hashimoto’s, you lab results can swing between hypo and hyper, & your lab test may be representing the middle of the swing.

T7, TOTAL T3 (no free in front), TOTAL T4 (no free in front), UPTAKE, etc: useless and outdated for our particular needs…

I am no good at posting links but I have a downloaded article named " Thyroid hormone replacement - a counterblast to guidelines" written by AD Toft.

TSH still has value, and is important for judging the overall picture. Your T3 and T4 are nicely within the range values - I know it feels counter-intuitive when you've reached this point, but could your doses be too high considering the very low TSH?

How are you feeling in yourself?

It's certainly worth properly discussing your fears/concerns with the GP, rather than just talking about articles.

I don’t have any answers, but in the name of solidarity, your results look very much like mine! My TSH is always 0.01, sometimes even when my T4 and T3 are low in range, or even below range. No one has ever been able to give me a satisfactory answer to this that I understand! I’ll watch the responses to your post with interest.x

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