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213044 tn?1236527460

Could someone explain "pooling"?

Free T3 pooling, or T3 pooling.

What is it, why is it, and how is it treated?
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Avatar universal
My dad was on T4 therapy for long time (had 1/2 thyroid removed) with all kinds of symptoms.  Turned out his RT3 was sky high and his T3 very low (and consequently his iron was low too).  He went on compounded T4/T3 and is doing much much better.
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Avatar universal
I have found this reverse condition to be not so temporary, It has been high for over 4 years. They(my last and present Dr.) did an ultra sound in Oct., one side is smaller than the other but no nodules. I have a big problem with cycsts forming in my body, kidney, lungs, ovaries, and vagina. I don't know if that would show on an US. I don't know if that could be causing the problem.
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Avatar universal
Just thought I would mention how the RT3 is not just a blood level. Dr Rind explained to me it is the body's way of regulation, for instance if you suddenly took too much T4 or your thyroid was diseased and too much was put out (as can happen in Hashis and Graves) your body can make this to slow your metabolism down. The main thing is though that it occupies your thyroid receptors, so if you have too much of that and less t3 and the receptors are occupied by the inncative hormone Rt3 then you feel ill as though hypo.
That is all I have heard. I would be interested to be honest in a test of someone with Hyperthyroidism/Graves to see how much RT3 is in their system, you would hope  for a lot to help slow down the metabolism, so not really sure how it works. I know the body doesn't just produce something for no use at all, and I do wish the scientists would do more testing on this subject.
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499534 tn?1328704178
Sometimes it is not self correcting unless you remove the T4 med until the reverse T3 levels go down. That is when T3 only is prescribed, so the patient doesn't suffer any hypo symptoms. My T3 level was in mid range and my dr still suggested the reverse t3 test to make sure my symptoms were not from that, and to make sure what meds she wanted me on. Even on Armour my T3 level is only mid normal range. My body must utilize it very quickly. My T4 level is mid range and tsh is .24 with no hyper symptoms at all. The only symptom I have left are brain fog and some joint pain. All else is incredibly improved and energy is becoming much better. It didn't happen this completely though until about week 11-13.  I can actually feel my body relaxing....you know how uptight and stressed it feels from the hashi's.  
Not sure about others, but just giving you an idea of why my dr ordered it.  
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213044 tn?1236527460
The up and down of a T3 med is why I am not interested in trying one unless I have to.

What I am trying to flesh out in this thread is Reverse T3 and pooling. The only info I can find on it says it lasts a few weeks. It is self correcting.

Why advocate testing and treatment for a transient condition?

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499534 tn?1328704178
Just wanted to add a quick comment on the fact that T3 is short lived.  Either a person has to take it 2 times a day, or have it compounded at a pharmacy into time release.
That link I gave you contains pros and cons both of T3....very interesting.
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314892 tn?1264623903
Without a thyroid gland, your body is relying on the t4 med to convert to enough t3.

I have read studies that say patients w/o a thyroid do convert enough t3. I am sure it is all individual.
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213044 tn?1236527460
Good point kitty.

Part of the overall picture is the condition of the gland. I was looking at it from the viewpoint of not having a gland.

Let us know what you find out.
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314892 tn?1264623903
I don't necessarily think the lack of enough t3 is a conversion problem. (In most cases. That is not to say it doesn't occur.)

The healthy thyroid usually puts out 20% t3 and 80% t4. Most of the t4 is converted into more t3. That is enough for someone with a healthy thyroid.

If someone's thyroid is damaged enough, perhaps they are not making enough t4 AND t3.

It is expected that the exogenous t4 (med) will be enough for the body to convert t4 into enough t3. It may not be enough for some people. Even if the t4 med converts to t3 in sufficient amounts, there may be less t3 overall if the diseased thyroid cannot make enough t3 to start with.

This is a question I have written down for my endo appt on Wed. I will post back if I am enlightened further.
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213044 tn?1236527460
The thing I don't like about Cytomel, is the short half life. That can't be good to metabolize it and utilize it so quickly that you spike and then it runs short later in the day.

I may try it someday. If I'm not feeling better in a few months, I'll consider it.

I think I can get my Free T3 at the right level when the correct med dose settles in. Until then, It's up and down the scale. Historically, I have been able to maintain a decent Free T3 even when my Free T4 was low. Without a thyroid, that may change now.

Why would I ask for a reverse T3?

My tests have not shown the need for one.
If my Free T3 was abnormally low in comparison to my Free T4, then I might ask for one.

If it's something that is an anomoly that lasts a month or two and they probably won't treat it, the only value of the test is to confirm that your Free T3 is low because you have a transient thing going on. Peace of mind for you, but over with before they treat you, if they treat you.

That's why I was wondering if it was a long term thing. It shouldn't show up two test cycles in a row if it's short term.

That, and I had forgotten a lot about it. I wasn't sure if it showed up as low Free T3, or normal looking Free T3.

So a decent Free T4 and a low Free T3 means either a conversion problem, or possibly a Reverse Free T3 problem. And that would be called pooling.  

Thank you. I'll check out the link.
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499534 tn?1328704178
http://www.qualitycounts.com/fpt3.htm      Here is a whole bunch of reading on T3, reverse T3, Cytomel, etc.
I googled Cytomel and reverse T3....bunch of diff reading
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499534 tn?1328704178
Lovely......Dr Lupo also doesn't think that treating with Cytomel has much benefit.
So many drs with so many diff opinions....***** doesn't it?
All I have to say to these drs is....if the patient isn't right yet try something else....when it comes to thyroid that is.
I think it would be worth it for you to ask for reverse t3....whatta got to lose????
Nadaaa.....crappy feeling....fatigue.....fog....etc....etc.....lol
And I would ask your dr to give you a trial of cytomel with your levo, you haven't tried that yet have you?
You know what I always think??? You need your thyroid to help with the conversion of T4 to T3....if you don't have a thyroid or yours is killed off,. then how the heck are you expected to convert properly??  
I always google high reverse T3 levels I think.
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213044 tn?1236527460
Oh, I wasn't making fun of Dr. Lupo. I just thought it was funny the thread turned up in my search.

I should have searched this site as well.
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213044 tn?1236527460
Well, I understand it a little better now.
Too bad they cut the link to Dr. Lowe's site.
All I did was Google reverse T3.
Maybe searching a different phrase will come up with something.
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213044 tn?1236527460
No, I've never had a Reverse T3 test.
I was just curious. I've been seeing it mentioned a lot.

Everything I remember reading about it, which is a lot of reading and very little recall, is that it's a temporary condition.

This is a hoot. While I was searching Google, I found this.

http://www.medhelp.org/forums/Thyroid/messages/1408.html

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499534 tn?1328704178
I know I have found a FEW other readings on reverse T3 other than this dr wilson.  Everything i have read has always noted temporary....but the exception of this lady. Maybe she is back on regular meds now too...not sure.
Did you have a high reverse T3 come back?
I don't know if i told you about a book that i had gotten and read...it is "What your doctor may not tell you about Hypothyroidism"  It is written by an endo named: Dr Ken Blanchard. It is filled with great information...he covers everything and treats with EVERY medicine. He covers every aspect of hypothyroidism.  He believes and treats most of his patients with a 98% T4 and 2% T3 with great success. He even treats with time release synthetics if that is what is called for. His book was fantastic and filled with soooo much info. Sorry it is off subject but when you find an endo who isn't stuck in his box of treatment it is refreshing. He accepts patients from all over and might even phone consult. Just a thought. I would get the book and give it a good read.
Mary Shoman wrote forwards for a bunch of these books that drs wrote, but none of the info inside the book is by her. She just spoke as a patient I think. She has nothing to do with his treatments and writings.
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213044 tn?1236527460
I found the source you quoted, Laura.

There is more to be learned from that article.



"Under certain conditions, the conversion of T4 to T3 decreases, and more reverse T3 is produced from T4. Three of these conditions are food deprivation (as during fasting or starvation), illness (such as liver disease), and stresses that increase the blood level of the stress hormone called cortisol. We assume that reduced conversion of T4 to T3 under such conditions slows metabolism and aids survival.

Thus, during fasting, disease, or stress, the conversion of T4 to reverse-T3 increases. At these times, conversion of T4 to T3 decreases about 50%, and conversion of T4 to reverse-T3 increases about 50%. Under normal, non-stressful conditions, different enzymes convert some T4 to T3 and some to reverse-T3. The same is true during fasting, illness, or stress; only the percentages change--less T4 is converted to T3 and more is converted to reverse-T3.

The reduced T3 level that occurs during illness, fasting, or stress slows the metabolism of many tissues. Because of the slowed metabolism, the body does not eliminate reverse-T3 as rapidly as usual. The slowed elimination from the body allows the reverse-T3 level in the blood to increase considerably.

In addition, during stressful experiences such as surgery and combat, the amount of the stress hormone cortisol increases. The increase inhibits conversion of T4 to T3; conversion of T4 to reverse-T3 increases. The same inhibition occurs when a patient has Cushing's syndrome, a disease in which the adrenal glands produce too much cortisol. Inhibition also occurs when a patient begins taking cortisol as a medication such as prednisone. However, whether the increased circulating cortisol occurs from stress, Cushing's syndrome, or taking prednisone, the inhibition of T4 to T3 conversion is temporary. It seldom lasts for more than one-to-three weeks, even if the circulating cortisol level continues to be high. Studies have documented that the inhibition is temporary.

A popular belief nowadays (proposed by Dr. Dennis Wilson) has not been proven to be true, and much scientific evidence tips the scales in the "false" direction with regard to this idea. The belief is that the process involving impaired T4 to T3 conversion—with increases in reverse-T3—becomes stuck. The "stuck" conversion is supposed to cause chronic low T3 levels and chronically slowed metabolism. Some have speculated that the elevated reverse-T3 is the culprit, continually blocking the conversion of T4 to T3 as a competitive substrate for the 5’-deiodinase enzyme. However, this belief is contradicted by studies of the dynamics of T4 to T3 conversion and T4 to reverse-T3 conversion. Laboratory studies have shown that when factors such as increased cortisol levels cause a decrease in T4 to T3 conversion and an increase in T4 to reverse-T3 conversion, the shift in the percentages of T3 and reverse-T3 produced is only temporary."

http://www.***.***

It sounds like a temporary condition.

Are there any links that don't involve Dr. Dennis wilson that discuss a less than temporary condition?
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499534 tn?1328704178
Your right most of it does say it is temporary. I am not sure how long the lady here has been on cytomel now, but maybe she is the tough case...lol
I think about it as the reverse T3 being our garbage disposal for T4 that is left over. When the garbage disposal gets too full because of an "overload", we cannot put anymore T4 meds into our system. You can only then put active form of T3 in until the garbage disposal is emptied and fixed. LOL  How is that comparison?? lol   Then from there the patient can go back to T4 meds.
I am not sure but I think it is called Wilson's syndrome....not sure though, don't quote me on it. lol
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213044 tn?1236527460
Everything I have read about reverse T3 says it is a temporary condition that self-corrects.

I don't understand how it becomes an ongoing problem, and why Cytomel would stop the process.
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499534 tn?1328704178
I know a lady here in fort myers that couldn't get better no matter what thyroid med she tried until her dr ran the reverse t3 and found it high. He then treated her with Cytomel and she is feeling great now and still taking the Cytomel.
Some people do get to go back on T4 meds or combo meds after levels have averaged out.
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168348 tn?1379357075
Good ? ... C~
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314892 tn?1264623903
I have read that in Euthroid Sick syndrome this occurs. The free t3 eventually recovers without any medication. In this situation, it is temporary.
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499534 tn?1328704178
Conversion of T4 to T3 and Reverse-T3: A Summary

The thyroid gland secretes mostly T4 and very little T3. Most of the T3 that drives cell metabolism is produced by action of the enzyme named 5'-deiodinase, which converts T4 to T3. (We pronounce the "5'-" as "five-prime.") Without this conversion of T4 to T3, cells have too little T3 to maintain normal metabolism; metabolism then slows down. T3, therefore, is the metabolically active thyroid hormone. For the most part, T4 is metabolically inactive. T4 "drives" metabolism only after the deiodinase enzyme converts it to T3.

Another enzyme called 5-deiodinase continually converts some T4 to reverse-T3. Reverse-T3 does not stimulate metabolism. It is produced as a way to help clear some T4 from the body.

Under normal conditions, cells continually convert about 40% of T4 to T3. They convert about 60% of T4 to reverse-T3. Hour-by-hour, conversion of T4 continues with slight shifts in the percentage of T4 converted to T3 and reverse-T3. Under normal conditions, the body eliminates reverse-T3 rapidly. Other enzymes quickly convert reverse-T3 to T2 and T2 to T1, and the body eliminates these molecules within roughly 24-hours. (The process of deiodination in the body is a bit more complicated than I can explain in this short summary.) The point is that the process of deiodination is dynamic and constantly changing, depending on the body's needs.

Incredibly AR it is an easy fix....lol....you treat the patient with straight T3 med like Cytomel. The usual doctor doesn't think of running the reverse T3 on a patient who doesnt get better. But sometimes it is the answer! AKA: reverse T3 pooling.
My dr just ran mine to check, but I just reached optimum level for the first time. And, I am finally starting to feel better.
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