Blood work before of after tirosint-what’s the ... - Thyroid UK

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Blood work before of after tirosint-what’s the difference?

Maramonro profile image
25 Replies

Hello everyone,

I need your advice. My doctor in the USA said that it doesn’t matter when you do the blood test and that it can be done after daily thyroid medication. I had TT and was told by the doctor in Greece to do the blood work before the medication, so not sure if there is a difference.

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Maramonro
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SeasideSusie profile image
SeasideSusieRemembering

Because exogenous thyroid hormone peaks in the blood 2-4 hours after ingestion, and there will be a rise in your FT4, then if you take your Tirosint before the blood draw you will get a false high FT4 due to the test measuring the dose recently taken. Therefore to get a result reflecting your normal amount of hormone you should take your Tirosint after the blood draw. Your doctor in Greece is correct.

Maramonro profile image
Maramonro in reply toSeasideSusie

Thank you for your reply. Wouldn’t then make more sense to do it in the evening or in the middle of the day before hormone starts wearing out? My problem is that when they measured my hormones 6 hours after tirosint my TSH was 0.01 and T3 and T4 perfect in the upper/middle range, which means by body perfectly responds to it and that is why we take it every day. So if blood test was done before the medication the results could be completely different, so if the dose is increased based on it, could it cause hyper symptoms in this case?

SeasideSusie profile image
SeasideSusieRemembering in reply toMaramonro

You asked what the difference was between doing the blood test before or after taking thyroid hormone replacement and I have explained it.

when they measured my hormones 6 hours after tirosint my TSH was 0.01 and T3 and T4 perfect in the upper/middle range,

6 hours after ingestion of exogenous thyroid hormone your FT4 will be slowly decreasing from the peak, it will not have reached the normal circulating hormone level.

At the end of the day, the results of a blood test show what hormone is in the blood at that particular moment the blood is drawn, it doesn't tell us what is in the cells, no test can do that, which is why it's important that we ourselves know what dose of hormone replacement is optimal for us, so how we feel is what should guide us, not a number and where it falls within a range.

Before blood tests were introduced patients were dosed according to their symptoms, since blood tests were introduced doctors have become slaves to numbers and ignore how the patient feels.

Your two doctors have differing views, only you know how you feel. If you are happy with your results where they are and how you did that test, and you feel optimally medicated, then stick to what you did for that test.

Maramonro profile image
Maramonro in reply toSeasideSusie

Thank you for your response. Yes, you are right, the best indicator is how we feel, but I have been feeling ok on 125, 137 and 150, so now I have noticed more hair loss and my dr. said because my TSH is almost 0, while others are in the range, and he assumes that more hair loss is due to being hyper. So not sure what to think. The test was done before I took daily tirosint. The weird thing is that my results were similar a month ago, and test was done 5 hours after tirosint.

SeasideSusie profile image
SeasideSusieRemembering in reply toMaramonro

We can't assume hair loss is due to being "hyper" (and we can't be hyperthyroid if we have hypothyroidism, it's not physically possible although we can be overmedicated). And just because your TSH is 0.01 doesn't mean you are "hyper", if your FT3 is in range you are not overmedicated. I have had suppressed TSH for as long as I've been keeping a record of my results - 25 years (although hypo/prescribed Levo for 45 years), and I've also been overmedicated at some point, but I haven't had hair loss.

Vitamin deficiencies can cause hair loss:

hubpages.com/health/16-Vita...

Maramonro profile image
Maramonro in reply toSeasideSusie

Thank you so much! I suspect he blames my continued hair loss to being over medicated, since TSH is low- given that my FTs are normal. The problem is I was vitamin and minerals and iron deficient throughout my life but my hair has never been affected or changed a bit. This all started after my unnecessary TT. It’s fruat because every time I had to deal with the doctors in my life they made me sick:(( thanks again for your support and advice- it always makes me feel better. I wish I knew about this forum before my TT.

Sarahlouise1980 profile image
Sarahlouise1980 in reply toMaramonro

Hi Maramonro, how long have you been having the hairloss? I only ask as I have been experiencing hairloss for six months now and I think I may be over replaced too. Has it only been on the higher doses?

Sarahlouise1980 profile image
Sarahlouise1980 in reply toMaramonro

Also how is your hair affected is it just shedding like mine?

Maramonro profile image
Maramonro in reply toSarahlouise1980

I started experiencing hair loss since I had my TT, and also when I was under medicated, which was up to recently most of the time. I have noticed some spelt occasionally when hairloss gets worse, and now after I increased to 150 i have noticed it has thinned more. Basically I lost half of my hair since the surgery and is finer than it used to be.

Maramonro profile image
Maramonro in reply toSarahlouise1980

It could be body reaction to more medication, or more hormones or less... that is a hard thing, because both under and over medication can cause the hair loss, and from what I read it could be thyroid hormone itself.

Maramonro profile image
Maramonro in reply toSeasideSusie

I would also like your opinion on this: my TSH before my TT was always between 1.5-2, and my ft4 is always near the levels where it has been before TT, no matter what dose I am on. Do you think then that I should aim now at my previous ranges or this is different given I don’t have a thyroid?

SeasideSusie profile image
SeasideSusieRemembering in reply toMaramonro

I'm sorry, I still have my thyroid so have no idea about when someone has had a TT.

What levels are "normal" for us when we are well, may not be appropriate when we are on thyroid hormone replacement - that is possibly correct for me who just has a thyroid that stopped working for whatever reason, but I really can't say for someone who doesn't have a thyroid any more.

shaws profile image
shawsAdministrator

At least the Greek doctor does know best. His patients are lucky. Whereas the USA doctor's patients may not reach a dose on which they feel well but will be given 'other prescriptions' to try to control remaining symptoms.

Maramonro profile image
Maramonro in reply toshaws

Well, I wouldn’t say Greeks are good, as this one scarred me into a surgery just because I had a large goiter, while Americans would never do that. My endo here seems to be responsive and willing to listen to my suggestions, for now;) will see, but I wanted to understand the rationale behind this rule, as it doesn’t make complete sense to me, especially given that hormone levels are changing throughout the day. How do we know which time of the day is the most accurate, unless they don’t change dramatically...and then early morning makes sense

shaws profile image
shawsAdministrator in reply toMaramonro

Forget blood tests, the aim is for us to recover our health and feel well. A blood test - no matter what time of day - would probably give a different result each time.

So all of the emphasis is 'how our body feels' and are symptoms being relieved. That's the best way to judge i.e. we are able to have a normal life with no clinical symptoms.

The reason that we advise early a.m. test, is that the TSH is highest then and prevents the doctor adjusting dose down if we have a 'later in the day' blood test.

One doctor I know of is that when the patient is diagnosed, only one blood test has been taken. Thereafter no blood tests are taken and all the emphasis is upon how the patient 'feels' and of course all vitamins/minerals have to be at an optimum level too.

In the past, before blood tests and T4 (levothyroxine) was introduced, we were always diagnosed upon our clinical symptoms and given NDT (natural dessicated thyroid hormones) which was gradually increased until we felt well and symptom-free.

naturalthyroidsolutions.com...

Maramonro profile image
Maramonro in reply toshaws

Thank you so much for your response. The problem is I felt ok while I was on 125, and 137 and now 150, the only thing that is different my heart finally beats over 60 per minute so I assume I am finally back to normal. But I have recently noticed more hair loss, so we did another test, before my daily dose of tirosint and TSH was 0,1 while others are in the range, so my endo assumes that more hair loss is due to being hyper. So not sure what to think. The test was done before I took daily tirosint. The weird thing is that my results were similar a month ago, and test was done 5 hours after tirosint.

helvella profile image
helvellaAdministrator in reply toMaramonro

Accuracy isn't the issue.

Yes, hormone levels do change throughout the day. But when you are on total replacement of thyroid hormone, there is a very definite and clear pattern which is related to when you take your dose.

FT4 will rise, as SeasideSusie said, for two or so hours after taking your dose. It will then tail off, slowly, until your next dose.

If you had a blood test in the first two hours, the FT4 would be shooting up quickly. Even five minutes difference in timing could be enough to see a noticeable change in a test result.

Similarly, though less dramatically, from the peak (let us assume two hours after taking your dose) for several hours FT4 will drop. As you approach your next dose, the rate of change will be at its lowest.

You get more consistent results from having your blood draw in that trough before your next dose.

Maramonro profile image
Maramonro in reply tohelvella

Thank you so much for your response. The problem is I felt ok while I was on 125, and 137 and now 150, the only thing that is different is that my heart finally beats over 60 per minute so I assumed I am finally back to normal. But I have recently noticed more hair loss, so we did another test, before my daily dose of tirosint and TSH was 0,1 while others are in the range, so my endo assumes that more hair loss is due to being hyper. So not sure what to think. The test was done before I took daily tirosint. The weird thing is that my results were similar a month ago, and test was done 5 hours after tirosint.

helvella profile image
helvellaAdministrator in reply toMaramonro

TSH doesn't (usually) change very quickly - it is FT4 that rises strongly, then fades. FT3 rises in response to a does of levothyroxine after about 48 hours.

I would definitely NOT use the word hyper (as in hyperthyroid) to refer to possible marginal over-medication.

It is possible that Tirosint peaks earlier, and therefore fades earlier (and faster?), than tablet levothyroxine. Five hours might be long enough for the FT4 to have dropped down close to the trough value.

Maramonro profile image
Maramonro in reply tohelvella

Thanks for your reply, I really appreciate it. This whole experience has been very frustrating and doctors always seemed to make things worse.

shaws profile image
shawsAdministrator

Avoid this doctor. He wont improve your health. I suspect he thinks it is 'easy-peasy' i.e. look at your TSH and if it is 'somewhere in range', he will think you're on a sufficient dose. We need TSH to be 1 or lower and Free T4 and Free T3 in the upper part of the ranges, but these are rarely tested.

If you've had a TT you would probably feel better with a T3/T4 combination (liothyronine/levothyroxine).. I believe in USA you can also source NDT (natural dessicated thyroid hormones) which is made with pigs' thyroid glands and has all of the hormones a healthy thyroid gland would have, i.e. T4, T3, T2, T1 and calcitonin

stopthethyroidmadness.com/

Maramonro profile image
Maramonro in reply toshaws

Thank you for your reply. You are right most doctors are bad, but this is the first time that the doctor takes into account my opinion and consider how I feel. Also after london and Greek doctors, he is the first one who tested FT3 and 4 without asking. I am just asking how do we know that early testing before the medication is the most accurate, that’s all.

shaws profile image
shawsAdministrator in reply toMaramonro

This is a link which might throw light on the topic.

verywellhealth.com/optimum-...

Maramonro profile image
Maramonro in reply toshaws

Thanks so much! I really appreciate it!

HypoF3XXY profile image
HypoF3XXY

Vs know sk y

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