TSH

[MMAndrea52]

Hi everyone what does it mean when they say my TSH remains undetectable?

[shaws Administrator]

This is an explanation which might be helpful:-

TSH is made by specialized cells in the pituitary called thyrotrophs. These cells are highly sensitive to the levels of circulating thyroid hormone in our body, and function like a sensitive thermostat.

If the levels of thyroid hormone drop, the pituitary gland makes more TSH to stimulate the thyroid gland to work harder and make more thyroid hormone. Accordingly, an increased level of TSH strongly suggests the presence of hypothyroidism.

Conversely, if thyroid hormone levels are too high, the pituitary gland shuts off production of TSH and the level of TSH will become low, or even undetectable, indicating a hyperthyroid state.

The reliance on TSH as a key indicator of thyroid status depends on normal function of the hypothalamus and pituitary. Patients with a history of pituitary disease may not always be able to produce TSH normally, rendering the TSH less than 100% reliable in some patients with known pituitary problems.

mythyroid.com/bloodtests.html

[MMAndrea52 in reply to shaws]

Thanks shaws. I think I get it ha. So it’s not dangerous then. I feel better on my now dose of 87.5 but keep getting emotional, and bad anxiety maybe I should lower the dose to 75 daily? I have no thyroid and weigh 8stone 10

[MMAndrea52 in reply to MMAndrea52]

Ps iv never been told I have pituitary problems.

[shaws Administrator in reply to MMAndrea52]

When you state "I feel better on my now dose of 87.5" I am assuming you are taking levothyroxine alone?

As you have no thyroid gland whatsoever I think it would be a kind gesture to give you a T4/T3 combination (Levothyroxine and liothyronine). I have my gland and cannot function without T3. You need a full thyroid function test and I doubt GP will do so and it consists of :

TSH, T4, T3, Free T4, Free T3. GP should definitely test B12, Vit D,iron, ferritin and folate. Deficiencies in these also cause symptoms. The aim is that we feel well and symptom-free. IF ONLT GPs and endos were aware that we actually get clinical symptoms and it should be their aim to prescribe sufficient so that we have none.

All blood tests have to be at the earliest possible, fasting (you can drink water) and allow a gap of 24 hours between last dose of levo and test and take afterwards.

Always get a print-out of your results with the ranges, for your own records and post if you have a query.

[diogenes Remembering in reply to MMAndrea52]

The recommended dose regime for someone with no thyroid is 1.6-1.9 mcg T4 per kg weight. You weigh 55 kg, so ideal dose should lie between 88 and 104 mcg T4. Disregard the TSH - the aim for someone who can handle T4 only is as above.

[greygoose]

Was your thyroid removed due to Grave's disease? If so, it's possible that your TSH will never rise. And, if your doctors are cutting your dose in order to raise your TSH, they are going to make you very ill. They should not be doing that. What they should be doing is giving you a complete thyroid panel : TSH, FT4, FT3, vit D, vit B12, folate and ferritin, in order to know what's really going on with you. It could be you're not converting very well, and that is making you bad. A dose of 87.5 mcg levo only is very, very low for someone without a thyroid.