Please help me understand results!

[michellerace1986]

Please could someone have a look at my tests results and help me understand!

[helvella Administrator Thyroid UK]

I think the results say:

Free T4 67.4 pmol/L (7.7 - 15.1)

Free T3 29.8 pmol/L (4.3 - 6.8)

TSH < 0.005 (0.34 - 5.6)

When you take carbimazole, it stops your thyroid making and releasing new thyroid hormone. (So long as the dose is adequate.)

But it can take several weeks until the thyroid hormone that has already been made in your thyroid, and what is in your bloodstream, goes down.

Taking propranolol (a beta blocker) helps - by reducing the effect of the high levels of thyroid hormone on your heart rate. And also by reducing the rate at which T4 gets converted into T3 (the active form of thyroid hormone).

Even if you take propranolol, it will only help reduce your heart rate a little bit.

[tattybogle]

Ok .. so as expected. These show you have too much thyroid hormone T4 and T3 being produced. and as a result your TSH (Thyroid Stimulating Hormone) has dropped to a level that is so low it can't be measured (that's what the [< 0.005] means).

The very high levels of T4 and T3... (T3 in particular, since it's the 'active' form of T4)... are what caused the shaky symptoms of Hyperthyroidism , and the carbimazole they have prescribed is to stop your thyroid being able to produce so much T4 and T3.

free T4 (fT4)..... 67.4 [ 7.7 -15.1]

this is very high .. [ a normal level would usually be between 7.7 and 15.1 if done at this lab] T4 is the hormone produced by the thyroid gland, you are making to much for some reason, so carbimazole will slow down how much you make.

free Triiodothyronnine (fT3).....29.8 [4.3 -6.8]

This is very high... [normal would be 4.3 -6.8]...... T3 is the 'active' version of T4.. some T3 is produced in the thyroid ,and some T3 is made from T4.

High levels of T3 cause hyperthyroid symptoms. Carbimazole will reduce your production and T4 AND T3.

TSH <0.005 [0.34 -5.6]

These levels are suggestive of either Graves disease antibodies causing the thyroid to produce too much T4/3.... or a thyroid nodule producing too much T4/3.

Sometimes Hashimoto's HypOthyroidism starts with a period of mild 'Hyperthyroid' results , but your levels of T4 and T3 seem too high for that to be likely.

The way to be certain if it is Graves disease causing the Hyperthyroidism is to test for some antibodies .. TRab (Thyroid stimulating hormone Receptor antibodies). This test usually has to be ordered by an Endocrinolgist, .....as GP usually only test for the antibodies which show in Hashimoto's HypOthyroidism .. these are called TPOab (Thyroid PerOxidase antibodies )

[michellerace1986 in reply to tattybogle]

Hiya I've had to reschedule for Wednesday these are my first bloods I'm scared it's going to be worse or the same I've been so shaky and all hot this week

[tattybogle in reply to michellerace1986]

i don't know exactly how long it takes for carbimazole to work, but as helvella said it works by stopping you producing any more T4/3.... it doesn't do anything to reduce what was already in the blood, so that has to get used up /or excreted /or recycled into inactive T2 or something called reverse T3, which is the body's own safety valve.

T3 lasts less long than T4 in the blood... T3 lasts 2/3 ? days before half of it is gone , then after another 2/3 days half of that remaining half is gone, and so on.

T4 has a 'half life' of about 7 days, so after 7 day's half of it is gone... and so on.

As well as this, it is also being used up by you, so don't worry it will go down after a few days/weeks, and now you are taking the carbimazole it will stop you making so much ,.....so the reason you still feel bad this week is because it just takes a bit of time for the carbi to work AND for the levels of T4/3 you already have, to go down.

Make sure you tell them at the blood test that you have only actually been taking the carbi for (however many days) it is now.... knowing this information will affect what they decide about the dose after the blood test.

Even of the blood test doesn't look much better yet, it will do soon. as long as you take the carbimazole regularly .

hang in there

x

[helvella Administrator Thyroid UK in reply to tattybogle]

i don't know exactly how long it takes for carbimazole to work,

Extremely fast - an hour or so.

With its short half-life, after a few hours it is fading fast. Which is why it is common to split dose (two or three doses a day) when hyperthyroid. Often this can drop to one dose a day in the longer term.

[PurpleNails Administrator]

Was this the test which lead to the hyperthyroid diagnosis and prompted the medication?

Those are extremely high levels, hopefully they have been brought down by the carbimazole.

Did you have another blood test today? That will show how well the medication is working and if it needs adjusting. So ensure you look over those results and compare. Don’t be surprised if your TSH stays low for longer, it can take a while to respond. The aim initially is for FT4 & FT3 levels to be in range.

Do you know what was included in the subsequent test? Ideally as well as TSH, FT3 & FT4. A test for TRab or TSI and nutrients are included.

If not it’s something to discuss & request in advance of the next test. Don’t attempt to get the nurse or phlebotomist to add it on at the time of appointment, they won’t have the authority.

[michellerace1986 in reply to PurpleNails]

This was first test bit I've not been feeling any better I having bloods Wednesday now as I had to reschedule

[PurpleNails Administrator in reply to michellerace1986]

Did your symptoms ease or change at all? Once you have a repeat blood test it will show how your levels have altered. You may need a little longer on carbimazole to feel the benefit or an dose adjustment.

[michellerace1986 in reply to PurpleNails]

No I still feel really hot and shaky and sick etc all my muscles ache its horrible