Low T4, normal TSH

[ROJAS123]

My TSH levels are normal but my T4's are low.  Not sure what this means since if my pituitary glands are producing enough TSH what is happening to make my T4's low?
Doctor wants we to take a THS 3rd generation and a CBC and basic Metab panel.

I have all the symptoms of hypothyroid, depression, fatigue weight gain, joint pain, have cold hands and feet and got grey hair at a very early age as well as suffered infertility but she has not mentioned that and just told me to take these additional tests, so I am confused.
.
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[gimel]

What doctors consider as normal TSH depends on the reference range they use.  The old range was .5 - 5.0.   Over 8 years ago the AACE recommended that the range should be changed to .3 - 3.0.  Unfortunately most labs and doctors have yet to adopt the new range.  

More importantly TSH is a pituitary hormone that is affected by so many variables that it is inadequate as a diagnostic.  At best it is an indicator, to be considered along with more important indicators  such as symptoms, and also the levels of the biologically active thyroid hormones, which are free T3 and free T4 (note these are not the same as total T3 and total T4).

FT3 is the most important because it largely regulates metabolism and many other body functions.  Studies have also shown that FT3 correlated best with hypo symptoms, while FT4 and TSH did not correlate very well at all.  So it is important that you be tested for both FT3 and FT4.  If the doctor resists, you should insist on it and not take no for an answer.  Remember that you are the customer.  

As far as why your T4's are low, I'd like to have you post the actual test result and reference range, please.   Also TSH please.  

I have  known of patients with pituitary issues that were somewhat similar, where the TSH was actually on the lower end of the range, so of course their FT4 and FT3 were low, resulting in hypo symptoms.  

So let's start with that.  There are a lot of  dedicated members here who will also be glad to provide you the benefit of their knowledge and experience.

[TAhypo]

Help to understand?  Endo says I'm fine, don't feel fine
T4 - 6.1 (Ref. Range 4.6-12.0
FT4 - .79 (Ref. Range .93-1.70)
T3 - 153.5 (Ref. Range 80.-200.)
FT3 - 3.51 (Ref. Range  2.00-4.40)
TSH - 1.410 (Ref. Range .270-4.200)

[Super_sally888]

Next step, as mentioned by Gimel, aside from the tests your doctor wants is to test FT3 and FT4.  Once you have results, please post them and the reference ranges.

Please also post your actual test results (and the reference ranges) from the tests already done.

[ROJAS123]

Thank you both!
As of December 16, 2010
T4                 5.09        Reference  6.09-12.23  UG/DL This was "flagged" L
TSH              1.12                         0.34-5.6  uIU/ml
TRIIODO       84.4                           54-149  NG/DL

Today I go for TSH 3RD Generation
                     CBC (Includes DIFF/PLT)
                    BASIC METAB PANEL W/EGFR

I should have the results of the above three early next week.

Thank you!
L

[gimel]

I suggest that you request that they test for free T3 and free T4, not the total T3 and total T4.  the latter are somewhat out of date and don't provide nearly as much useful information as the test for the Frees.  If they resist and give excuses as to why it is not advisable, just insist on and don't take no for an answer.  Remember that you are the customer.  If you get agreement, then also make sure the lab people know it is to be free T3 and free T4, not the Totals.  You wold not believe how often mistakes are made and you end up with the Totals.  

If they have not ipreviously dentified the need to check your pituitary function, then I would strongly suggest that you try to get that done as well.  A low functioning pituitary would fit the pattern of test results that you have had, namely low TSH, with low T4.  

[ROJAS123]

Not sure if I am misreading your post, but my TSH levels are not low....they appear to be right in the mid range1.12 in a ref, level of 0.34-5.6 it is the T4's that came in low 5.09 in a ref, range of 6.09-12.23.The test I had today is not another TSH total,,,,it is TSH 3rd generation which I think has only recently been used,  It is far more specific that the first THS test I had done,  
I will ask about having freeT3 and freeT4 since from what i have read it allows testing without the protein attachments confusing the results.
I will post once I get the result from todays test...I think I can pick them up tomorrow.  I will be seeing doctor early this week to discus the results of todays tests.
Thank you again,

[gimel]

I should have been clearer and said that your TSH was relatively low in the range, taking into consideration your low T4 result.  They usually show in opposite positions within their ranges.  A low T4 will usually be accompanied by a higher T4.  When the results are more like yours, that can be an indicator that the pituitary signal (TSH) is weak, resulting in low T4 levels.  You should discuss this with doctor at next appointment.  Also make sure to get the FT3 and FT4 tests done, to help in diagnosis and treatment.

[jentri]

if it is the pituitary signal, what can they do to fix the problem?

[gimel]

It isn't a very satisfying answer, but it depends on the cause.  Relative to having low thyroid hormone levels, and hypo symptoms, the answer for that is medication to relieve symptoms.  Unfortunately in similar situations,  many patients never get thyroid meds, because their doctor only looks at TSH and tells them their thyroid is good, symptoms must be from something else.

[ROJAS123]

Haven't spoken to doctor yet but yesterdays blood work came out more confusing to me,
TSH 3rd generation is 1.02 with a reference of 0.34-5.6 ...on the low side but certainly within the range.
The blood work and chemistry was a bit more (I think) concerning,
HGB 14.3  H (ref. 12.0-14.2)
Neut 35 L,
Lymphs 53.0 H
LY# 3.71 H.
Chemistry BUN 23 H, BUN/CR RA 33 H, and CO@ 37.0 H....wbc 7.0 and rbc 4,45 both ok.
So, now I don't know if this new information suggests that I don't need to take  a Free T3 and Free T4 since it is something else or if I still should insist on both tests.
L

[gimel]

With the symptoms you listed above, be sure to  get the FT3 and FT4 tests done.

[gimel]

Here is a link to a bit more information on the pituitary.

http://www.webmd.com/a-to-z-guides/hypopituitary

[ROJAS123]

Thank you. If doctor does not suggest Free T3 and Free T4 I will tell her I want it done.
WIll these tests be able to determine if I am in fact Hypo?

[ROJAS123]

THANKS AGAIN...i will let you know what the Dr. has to say. Either way, I will insist on getting the FT# and FT4 if she doesn't.
L

[ROJAS123]

before I drive myself crazy(er) I thought I would ask if you know what two of my more trobling (to me) test results signify. Needless to say, I have not gotten a cll back from my doctor let so I my be doing a bit too much reteach with out enough knowledge on what it all means.  My co2 is high (37.0 as are my HGM 14.3.
The most troubling to me is a GFR of 86. Not sure if this has anyting to do wit being Typo or if this is just in addition to it.
thX

[gimel]

I have no experience or knowledge to offer on those tests, other than what I see on the 'net, which I'm sure you have already gone through.  So I think you should give your doctor a chance to get back to you and answer those questions.

[ROJAS123]

Results were discussed with Doctor last night, Other than my CO2 levels being high (could be breathing shallowly) all else is o.k.  Still does not explain my Hypothyroid systems and the Low T4.  She is still insisting that the TSH (3rd generation) which "tells you what the brain is doing" means that I am NOT hypo. I was so relieved to find out that I didn't have Leukemia, Kidney or liver problems I hung up without insisting on the Free T tests. Do I have the right to call her back and insist on getting these other tests? I would think that there must be something going on if my T4 results were low and my symptoms are on in line with the Hypo..  I have a good relationship with my primary doctor who I have got to for 20 years,. If the endocrinologist (no history until 2 weeks ago) wont authorize, can I have tests ordered by him?
L

[gimel]

Again, remember that you are the customer.  You can call back and ask for whatever you think is necessary.  If the doctor resists, then just insist on it and don't take no for an answer.  One of our members claims that in a similar situation, she told the doctor she was going to get a big chain and lock and lock herself to his desk until he relented and did the testing she wanted.  Others have found that tears worked.  LOL   If need be, then get your primary to do the resting.  Whatever it takes.

The bigger issue for you I think is that even after getting the testing done, where are you going to find the good thyroid doctor that will treat you clinically by testing and adjusting FT3 and FT4 adequately to relieve symptoms?  Unfortunately, an Endo is not usually so inclined.  They tend to be more rigid and only look at TSH, or if they test beyond TSH they consider any result within the reference ranges as "normal" and don't want to do anything to relieve symptoms.  Do you have any prospects for finding a good thyroid doctor?

[ROJAS123]

NO I do not have a thyroid Dr. I did however get a script for Free T3 and FT4.
Taking those on Friday. Endo is female so she is a bit more willing to go with what I ask...even if she thinks THS is the way to go.
What are numbers for The F t3 and F t4?
L

[ROJAS123]

Free T3 and Free T4 are in the "range". FT4 is 0.75 (range is 0.548-1.64)
and FT3 IS 2.9 (range is 2-3.5)
This doesn't seem to explain my symptoms, my low T4 of 5.09 or my enlarged Thyroid.
I did an Iodine Patch, at the suggestion of a nutritionist friend, and within 8 hours after applying is it totally disappeared.
All of the other tests seem to be normal so I am at a loss to know what to do now.
L

[gimel]

The thing you need to do is to get your doctor to prescribe meds for you to increase your FT3 and FT4 adequately to relieve your symptoms.  I would suggest that you give the doctor a list of your symptoms that you have mentioned, along with a copy of this letter, and ask her to prescribe enough meds for a therapeutic trial.  

http://hormonerestoration.com/files/ThyroidPMD.pdf

If the doc resists, then ask her for an explanation of your symptoms, if she says it is not thyroid related.  

[ROJAS123]

Thank you. I truly appreciate your taking the time to respond and to send met the link to information that will help me to persuade my doctor to start a "clinical trial".

FYI I ordered some Iodoral...figured in the interim it couldn't hurt and possible could do some good,

[Nina_11]

I think you might want to do some checking into the free T4. Generally, the school of thought is that the low end of the range is .8 (.548 seems like a very low reference range). My free T4 is .75 and is considered hypo by my doctor. I'm new to the board, so others might want to chime in :)


Adult Reference Ranges:

FT4 = 0.8-1.5 ng/dl

[ROJAS123]

Thank you. My endo still says that I am in the normal range....very frustrating.
May I ask what sate you are in? And who is your doctor, perhaps he could recommend one to me in New Jersey.