Aa
Aa
A
A
A
Close
Avatar universal

Low TSH, normal T3 & T4

A little history.  About 10 years ago I was treated with PTU for hyperthyroid, for about 2 years. This was because I was pregnant, then breastfeeding.  I recently started having some minor symptoms, palpitations, hot flashes, mild weight loss.  I went in and my TSH was low, but T3 & T4 were normal.  Doc sent me to an endocrinologist, who retested me, and said that my numbers changed dramatically in a weeks time.  My T3 & T4 were still normal, however.  He has recommended RAI and I'm scheduled to take it this coming Friday.  The tech doctor said my case is not a-typical, that he really has never  treated anyone with my numbers being what they are.  He told me I might want to wait it out, but would do some research to see if maybe there is something that tells him what is the best route.  Now, I'm really confused on what I should do.  Should I do the RAI, or is is best to take the wait and see approach?  
11 Responses
Sort by: Helpful Oldest Newest
Avatar universal
I am aware that there are side effects with taking the medication, but I would like to get more tests done this week and see what they say.  I do know that because of my history, the doctor's thoughts were that we could treat it again with meds, but ultimately, it could again come back and we would be looking at treatment options again.  I have several family members with thyroid problems, but do know that they can sometimes die off on their own and I guess that I can only hope that the same happens with me.  Thank you!
Helpful - 0
Avatar universal
FYI:

Although antithyroid medications are commonly used as first-line treatment, only 20% to 30%  individuals treated medically will experience long-term remission. Thus, either surgery or radioactive iodine is needed to achieve long-term cure for most pediatric patients with Graves’ disease.

There are side effect issues to all the other antithyroid drugs - ATDs.

ATDs on the other hand are more "foreign" to the body, and the by-products of these drugs metabolization in the liver are toxic. If the liver can process these by-products out quickly enough, you do not get adverse side effects typically. But as the liver slows down, or becomes less efficient (and it does this, naturally, as we age), those toxic by-products can build up, leading to problems. One of these problems involves damage to the liver itself.  You should weigh the plusses and minusses of treatment options and try to pick the one that is safest for you, long term. In some patient's cases, their doctors recommend long-term use of the ATDs.  Just because some people take ATDs long-term, that does not necessarily mean we all should or could. This is where a really good heart-to-heart with the doctor is important.
The ATDs only control thyroid hormone production -- they offer no cure of the disease. Sometimes (approximately 30% of the time, optimistically) people experience a remission which is, by definition, a temporary alleviation of symptoms. In our case remission means that for some unknown reason, the antibody levels subside for a period of time. But the disease will come back, making us ill again. Remission does not mean "cured".  It means a respite. You need to look at what is safest for you , long-term. So, if liver damage or other major side effect issues are being weighed in, it is often safest to do RAI  and go onto replacement hormone for the longer term treatment. We can and do live well without a functioning thyroid. However, we cannot live at all without a liver.
While taking ATDs the thyroid levels are fluctuating all the time due to  changing antibody levels. No one knows why the antibody levels go up and down, but as long as there is a thyroid it will affect the person and cause symptoms.      It is very difficult to get pregnant or maintain a pregnancy while thyroid levels are fluctuating.
The sooner levels are normal and stay that way the sooner a person will feel better. It  may take a while to reach after RAI or surgery, but it's much more difficult on ATDs, especially if there wasn't success early on with them.

Tuttle et al (Thyroid 5:243, 1995) have shown that treatment with ATDs before radioactive iodine therapy is associated with a higher treatment failure rate than therapy with radioactive iodine alone in Graves' disease. Thus patients treated with PTU may require a greater radioactive iodine dose to ensure adequate treatment of their disease.
Randomized clinical studies show that pre-treatment of patients with antithyroid drugs prior to radioactive iodine results in more severe transient rebound hyperthyroidism, compared to patients who received radioactive iodine without pretreatment. For an overview, see J Clin Endocrinol Metab 1999 Nov;84(11):4012-6 Effect of methimazole pretreatment on serum thyroid hormone levels after radioactive treatment in Graves' hyperthyroidism and The effect of antithyroid drug pretreatment on acute changes in thyroid hormone levels after (131)I ablation for graves' disease. J Clin Endocrinol Metab. 2001 Jul;86(7):3016-21


Some doctors try to adjust the dose of radioactive iodine to destroy only enough of the thyroid gland to bring its hormone production back to normal, without reducing thyroid function too much; others use a larger dose to completely destroy the thyroid. Concern that radioactive iodine may cause cancer has never been confirmed.  Usually RAI is a non-event, meaning that one feels nothing unusual. One may get a slight sore throat several days later.  One may feel extremely HYPER within a week of having RAI due to the mass dumping of excess thyroid hormones.



The RAI dose that Gravers' or Hashitoxicosis get is equilivant to on x-ray or a day out in the sun which is a very small dose.
Hyperthyroidism                                                             4 to 10 millicuries
with a High mean dose of 12.7 +/- 7.5 millicuries
Hyperthyroidism/Graves' disease  low-dose is radioiodine   2 mCi
Toxic nodular goiter and other special situations              11 to 15 millicuries

Good luck with your decision.

Helpful - 0
Avatar universal
FYI:

Although antithyroid medications are commonly used as first-line treatment, only 20% to 30%  individuals treated medically will experience long-term remission. Thus, either surgery or radioactive iodine is needed to achieve long-term cure for most pediatric patients with Graves’ disease.

There are side effect issues to all the other antithyroid drugs - ATDs.

ATDs on the other hand are more "foreign" to the body, and the by-products of these drugs metabolization in the liver are toxic. If the liver can process these by-products out quickly enough, you do not get adverse side effects typically. But as the liver slows down, or becomes less efficient (and it does this, naturally, as we age), those toxic by-products can build up, leading to problems. One of these problems involves damage to the liver itself.  You should weigh the plusses and minusses of treatment options and try to pick the one that is safest for you, long term. In some patient's cases, their doctors recommend long-term use of the ATDs.  Just because some people take ATDs long-term, that does not necessarily mean we all should or could. This is where a really good heart-to-heart with the doctor is important.
The ATDs only control thyroid hormone production -- they offer no cure of the disease. Sometimes (approximately 30% of the time, optimistically) people experience a remission which is, by definition, a temporary alleviation of symptoms. In our case remission means that for some unknown reason, the antibody levels subside for a period of time. But the disease will come back, making us ill again. Remission does not mean "cured".  It means a respite. You need to look at what is safest for you , long-term. So, if liver damage or other major side effect issues are being weighed in, it is often safest to do RAI  and go onto replacement hormone for the longer term treatment. We can and do live well without a functioning thyroid. However, we cannot live at all without a liver.
While taking ATDs the thyroid levels are fluctuating all the time due to  changing antibody levels. No one knows why the antibody levels go up and down, but as long as there is a thyroid it will affect the person and cause symptoms.      It is very difficult to get pregnant or maintain a pregnancy while thyroid levels are fluctuating.
The sooner levels are normal and stay that way the sooner a person will feel better. It  may take a while to reach after RAI or surgery, but it's much more difficult on ATDs, especially if there wasn't success early on with them.

Tuttle et al (Thyroid 5:243, 1995) have shown that treatment with ATDs before radioactive iodine therapy is associated with a higher treatment failure rate than therapy with radioactive iodine alone in Graves' disease. Thus patients treated with PTU may require a greater radioactive iodine dose to ensure adequate treatment of their disease.
Randomized clinical studies show that pre-treatment of patients with antithyroid drugs prior to radioactive iodine results in more severe transient rebound hyperthyroidism, compared to patients who received radioactive iodine without pretreatment. For an overview, see J Clin Endocrinol Metab 1999 Nov;84(11):4012-6 Effect of methimazole pretreatment on serum thyroid hormone levels after radioactive treatment in Graves' hyperthyroidism and The effect of antithyroid drug pretreatment on acute changes in thyroid hormone levels after (131)I ablation for graves' disease. J Clin Endocrinol Metab. 2001 Jul;86(7):3016-21


Some doctors try to adjust the dose of radioactive iodine to destroy only enough of the thyroid gland to bring its hormone production back to normal, without reducing thyroid function too much; others use a larger dose to completely destroy the thyroid. Concern that radioactive iodine may cause cancer has never been confirmed.  Usually RAI is a non-event, meaning that one feels nothing unusual. One may get a slight sore throat several days later.  One may feel extremely HYPER within a week of having RAI due to the mass dumping of excess thyroid hormones.



The RAI dose that Gravers' or Hashitoxicosis get is equilivant to on x-ray or a day out in the sun which is a very small dose.
Hyperthyroidism                                                             4 to 10 millicuries
with a High mean dose of 12.7 +/- 7.5 millicuries
Hyperthyroidism/Graves' disease  low-dose is radioiodine   2 mCi
Toxic nodular goiter and other special situations              11 to 15 millicuries

Good luck with your decision.

Helpful - 0
Avatar universal
I backed out of my RAI treatment today.  I feel I was rushing to a decision, that ultimately, once it was done, I could not take back.  I have a call into the doctor to let him know and that I would like to look at taking medication for now.
Helpful - 0
Avatar universal
Oops!! I meant my TSH went from .129 ot .069, I missed the zero after the decimal.  So, it did in fact go down.  I'm going in at 3 pm today and I have a call into my doc to just speak with him once more before making my final decision.  The Nuke doctor called and said although my numbers are not a-typical of those they usually treat, he did say that the latest consensus is to treat, although it is a bit controversial.  I was having symptoms, so that did help in determining to treat me.  I have not really experienced any palpitations in the last couple of weeks, however my moods are horrible.  I am irritable all the time, and this has only come about since my thyroid starting acting up.  It's very difficult to make a decision, since it is one that I can't take back, as alysmum said.  I can't imagine that my doctor would make the decision to treat unless he really felt it was necessary.  There are no benefits for him and I fear not doing it will cause me to have more serious problems.
Helpful - 0
Avatar universal
I have no idea what the right answer is, but I would not rush into this treatment unless I was sure that it was the right thing for me.  Is there a reason to hurry into this?  Your endo is looking at this from a physicians standpoint; You should make the final decision.  It doesn't sound like you've given your body the chance to balance itself out.  If you are not sure yet, just wait.  Don't rush into something that you can't take back.





Helpful - 0
Avatar universal
Thank you for your response.  I'm sitting here struggling with the fact that my RAI treatment is 24 hours away and I am not sure that it's the right thing to do.  I felt like it was a haste decision, but didn't think my endo would advise me on doing this if he didn't feel it was for the best.  I forgot to mention I did do a thyroid scan, which was only slightly abnormal, but abnormal nonetheless.  I am so moody, along with all my other symptoms.  I just hoped that by doing this it might be a cure all for several things.  How do do you know what the right decision is?
Helpful - 0
Avatar universal
Most doctors say that.

I assume you are not on meds. now or when these levels were done.
TSH of .69 is higher than TSH of .126, so your TSH went up, not "dropped", which HIGHER is heading in the correct direction.  When the TSH goes up, T-4 will go down, in other words, will go the opposite direction as the TSH.  The difference could be error or different Labs.

Some thyroid levels will eventually return to normal.  With this in mind you might wait for treatment with regular testing to keep up with what your levels are doing.  As it is, TSH of between 0.1-0.45 mIU/L) likely poses no harm, and initiating treatment likely poses no clear gains - per US guidelines.

Although with both TSH and T-4 low might indicate other problems going on such as allergies, hormonal imbalance, yeast, adrenal fatigue or hypothyroidism due to low pituitary function, etc.   Without knowing your T-3 in how it is relating to T-4, its hard to relate.  By the way, if you are estrogen female FT-4 should be done because estrogen interferes with T-4 level where estrogen does not interfere with FT-4.

Don't know if any of this is of help, but good luck anyway.

Helpful - 0
Avatar universal
Nobody has any comments?
Helpful - 0
Avatar universal
Anyone?
Helpful - 0
Avatar universal
I don't know how to edit, so am just posting a follow up.  I found my test results.  My TSH was .129 one week and the following it had dropped to .69.  My T4 was 1.08 and the following week was down to .98, I don't have any comparisons for the T3 since the first doc never did that test.   I am looking at these thinking that since they are dropping so quickly, that it tells me that maybe my hyperthyroid is getting worse and should be treated with the RAI.
Helpful - 0
Have an Answer?

You are reading content posted in the Thyroid Disorders Community

Top Thyroid Answerers
649848 tn?1534633700
FL
Avatar universal
MI
1756321 tn?1547095325
Queensland, Australia
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
We tapped the CDC for information on what you need to know about radiation exposure
Endocrinologist Mark Lupo, MD, answers 10 questions about thyroid disorders and how to treat them
A list of national and international resources and hotlines to help connect you to needed health and medical services.
Herpes sores blister, then burst, scab and heal.
Herpes spreads by oral, vaginal and anal sex.
STIs are the most common cause of genital sores.