Thyroid UK
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Can someone explain this excerpt taken from Thyroid UK

"However, there has been recent evidence to show that it may be safe for patients taking long-term thyroxine replacement therapy to have a low but not suppressed TSH level. The patients who took part in the study who had very high (more than 4.0mU/l) or suppressed (less than 0.03mU/l) TSH levels more frequently suffered from heart disease, abnormal heartbeat patterns and bone fractures compared to patients with TSH levels in the normal range (0.4-4.0). Patients who had a slightly low TSH level (0.04 – 0.4mU/l) did not have an increased risk of contracting any of these conditions."

Is this saying that TSH of 0.03 or lower is bD for the heart and that TSH 0.4 do not have heart problems???

5 Replies

Also, remember a lot of medical statistics are presented in a bell curve. So 0.03 means that SOME people will have problem with it in the future but not all and the risk is much higher (and presumably not currently recommended). As they can't test everyone in the study and predict what the outcome might be, you also won't know if there is any preexisting likelihood of anyone in the study who would get heart problems anyways without the suppressed tsh through genetics, lifestyle etc.

i.e. you can have 0.03 tsh and never get heart problems and you can have 4.0 tsh and get heart problems, but they think that you are much more likely to be 0.03 tsh and get a heart problem.

So, in essence, nothing too much to worry about. They change these numbers sometimes depending on how they feel. Shrug.

Personally I rather feel awesome now and die of a heart attack in 30 years time rather than live till 80 and feel crap for another 50 odd years.


I am 0.03 but sometimes <0.03

I have HARD heartbeat and wondered if it was due to TSH being so low??

Never had this when I was in the 1's or 2's


I am not a medical professional but I believe that when you're medicated for thyroid problems you need to look at your t4 and t3 levels to see where you're at. The tsh test is literally useless. TSH is the pituitary hormone that tells your thyroid gland to make t4 (which then gets converted to the active hormone t3) so if you're on any type of thyroid replacement hormones you should have enough in your body so the feedback to the pituitary is "enough t4, no more tsh" and therefore resulting in a suppressed tsh (because you are ingesting the stuff orally and therefore you don't really need to make much of it).

If you feel your heartbeat is HARD (I assume you mean thumping here) might be worth checking your blood pressure at the doc to make sure everything is ok. You can easily check your heart rate by taking your own pulse manually (or most smartphones will do it for you nowadays).

And as I mentioned above, you could have 1or 2 tsh and still developed a racy heart or high blood pressure, it doesn't mean if you tsh is <0.03 you MUST have a heart problem and it MUST be because of your tsh. It's all statistics and probabilities of what *might* happen, and what is happening could be stemmed from the thyroid or somewhere else.



There is thought amongst many doctors that a high or suppressed TSH has the risk of heart disease and bone fractures. I believe this true in a proportion of the population but in another proportion it is actually necessary to medicate a certain amount of T4, that will suppress the TSH, in order to achieve well being. Wellbeing means homeostasis and heart problems and bone fractures would be of little risk. Then there is another subset, who will never achieve well being, no matter how much Levo they medicate and how suppressed their TSH be, as they require additional T3 hormone replacement.

However, (it appears) that even medicating T3 in multi doses can further induce more complexities as the pituitary may be sensitive to the unavoidable peak T3 levels and so over-respond, reducing TSH levels in totality.

All previous efforts to raise my TSH levels have always failed, although I function well with LOW thyroid hormone (but meaning there is no room for a med reduction) as am convinced of the downgrading re the hypothalamic/pituitary axis, due to the state of hypo-metabolism that low thyroid function may induce.

TSH levels would be low anyway in the presence of a pituitary or hypothalamus issue & do not consider problems accurately in the adrenals or immune system to gauge whether thyroid hormone is adequate, sufficient or excessive. Only we are the best judge of how our meds are working as know our basal temps, pulse rate, and symptoms.


If you are taking0 thyroid meds of any kind then TSH is irrelevent.


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