What range is hyperthyroidism?

Hi everyone,

I had my bloodwork done awhile back and my tsh was .05. Do you think a tsh of .05 is hyperthyroidism?

[greygoose]

A TSH on its own cannot tell you if you are hyper. You need the Frees tested as well. If your FT4/3 are both very over-range, you are hyper. But, for all sorts of reasons, your TSH could be low, but your Frees in-range.

[Hidden in reply to greygoose]

I always thought diagnostic criteria for hyperthyroidism to be based on Tsh. If you have a high tsh and normal t3 and t4 wouldn’t it be secondary hypothyroidism?

[greygoose in reply to Hidden]

Depends on the level of the T3 and the T4. 'Normal' just means 'in-range'. But, the ranges are usually wide, so it depends where in the range the results fall.

But, no, secondary hypo is where the TSH is low, but so are the FT4 and the FT3, because secondary hypo is caused by the inability of the pituitary to secrete enough TSH to stimulate the thyroid to make more hormone. So, there, you would be hypo even with a low TSH. Which is one of the reasons a low TSH on its own cannot be used to diagnose hyperthyroidism.

[Hidden in reply to greygoose]

Greygoose wouldn’t the t4 and t3 be normal and the tsh high because the pituitary struggles to make enough tsh therefore the tsh would be higher due to the output to make t4 and t3.

[greygoose in reply to Hidden]

No, if the pituitary is struggling to make TSH, the TSH would be low. Like thyroid hormone is low when the thyroid is struggling to make it. As for 'normal', all that means is 'in-range', and most ranges have little to do with normal.

[Hidden in reply to greygoose]

Greygoose,

I appreciate your explanation and this is something that I will pay attention to the free t’s more. I felt benefit from my thyroid medicine but I just felt at times overmedicated at first. My doctor originally prescribed 75mcg as a starter dose. I think she should’ve start me off at 25-50mcgs.

Thank you,

Solly

[greygoose in reply to Hidden]

50 mcg would have been best. But, very few of them know how to dose.

[Hidden in reply to greygoose]

You’re so right and I wish she had more experience dosing.

[greygoose in reply to Hidden]

It's not really a question of experience, I don't think. The learn something in med school and it becomes sacred, they never question it. If she learnt it wrong, I doubt she will ever change.

[Hidden in reply to greygoose]

True you’re right about this. They all have the same approach and you know it’s the same train of thought.

[Angel_of_the_North in reply to greygoose]

Or if the hypothalamus isn't sending a signal (TRH) to pituitary to tell it to produce TSH (tertiary hypothyroidism).

[greygoose in reply to Angel_of_the_North]

Yes, it could be. There could be several reasons why the pituitary doesn't produce enough TSH.

[SeasideSusie Remembering]

SollyOno

It can be, and it can't be.

I have quite a few TSH results showing <0.005, <0.01 and 0.01 but I am hypOthyroid. The reason my TSH is that low is because I am on Levo and the pituitary is detecting there is enough thyroid hormone so doesn't need to send the signal (TSH) to the thyroid to produce it.

It can also be that when someone has Hashimoto's (autoimmune type of hypothyroidism) and they have had a spurt of antibody activity and the dying cells have dumped a load of hormone into the blood which has made TSH suppressed and FT4/FT3 high.

It can be hyperthyroidism, but you would generally see an over range FT4/FT3 and positive Graves antibodies.

So it depends entirely on the circumstances.

[SilverAvocado]

SollyOno, just seen that you are on thyroid hormone replacement. If you feel you're overdosed, that's a not the same as being hyperthyroid, which is when your own thyroid produces too much hormone. But doctors often get confused about the difference.

If you feel undermedicated, and your doctor isn't doing much to treat you, you could always try dropping to 50mcg on your own and see how you feel. Levothyroxine is a very slow acting treatment, so you may have to wait a few weeks to see any difference. Ideally stay on the new dose for 6 weeks till everything has settled down.

You can order pin prick mail order bloods tests from Blue horizon or Medichecks if you want to be sure. You need TSH, free T4 and free T3. Or if you want to confirm Hashimotos get both antibodies as well. If the budget isn't too tight, you might as well look at your vitamins, ferritin, folate, vit D and bit B12 at the same time. Thyroid problems can deplete all of these, and they're needed to get full benefit from the hormone.

[healthymarge]

6 months ago my TSH was 0.02 so gp lowered my dose of eltroxin from 100 to 75. Next blood test two months ago TSH was 23.50 so gp said to go back to 100. Latest TSH is 12.3 so gp said 100 Mon to Fri and 75 weekends. What is going on? My nails and hair have stopped growing and have to take a laxative every night. Also heart is skipping a beat. Fed up going to docs😫

[SeasideSusie Remembering in reply to healthymarge]

Healthymarge

If you start a new thread with your question members will comment.

[Hidden in reply to healthymarge]

Healthymarge,

I’m sorry to hear that you’re going through a tough time with your treatment. I hope you start feeling better and you will keep me updated on your progress. Please also let your doctor know that the medication or medication strength might not be right.

[healthymarge]

Just got results back and B12 and Vit D and T3 not checked! I give up. Not going back to my gp. Will check things myself!

[Hidden in reply to healthymarge]

Hi healthymarge,

I know how frustrating it can be but just stay positive. Maybe you can go to another doctor. I would try to keep looking until you find a gp that he/she will understand you.

[healthymarge]

No matter how many docs I go to they only look at blood test results and not symptoms. Will do some more research myself and see do I improve.😁

[Hidden in reply to healthymarge]

I can relate if it’s in the normal range then they typically don’t bother to help. I do have visible symptoms like premature grey hair, hair patches, insomnia and metabolic issues. I have managed to find a sympathetic doctor. I hope you will find one too. 😊