Low FT3 and FT4 - normal TSH

[JoStafford]

Hello,

Can anyone please help me with my problem?  I have had an underactive thyroid for 3 years and have felt terrible nearly every day.  

My last blood test my results in Sept 09 were:

TSH - 1.5 (1-5.5)
FT4 - 10.1 (9.9-25)
FT3 - 4.4 (3.9-6.5)

As you can see, my FT3 and FT4 levels are at the low end whereby my TSH is within normal limits.  I guess this means I have have conversion problems.  I take 75mg of T4 and 5mg of T3.   My Endo suggested I increase the T4 to 100/75 on alternating days.  This gave me huge anxiety attacks and insomnia so I reduced it back down to 75mg.  

I am due a blood test in January.  The test is for TSH, FT4, FT3, Vit D (I was vit D deficient), Calcium and RT3.   Does anyone know what other tests I can ask for?  My DHEA was normal in my last test.

I've read a bit about conversion problems and know it could be due to adrenal, liver and digestive enzyme deficiencies.   Are there any blood tests I can do to find out whether these are the problem?

Thanks so much for any advice here.

Jo

[goolarra]

I'd just like to jump in here and correct one of your misconceptions from a couple of posts up:

"I know about cases in which the FT3 and FT4 when there gland is balanced are the same as when being diagnosed as primarily hypo ,however ,the reduced the TSH and have the tens of symptos gone !"

You have to understand that the level of TSH in your blood causes NO hypo or hyper symptoms, no matter what level it is.  Changing your TSH level, per se, does nothing to alleviate symptoms.  TSH is nothing more than a messenger from your pituitary to your thyroid to tell it to produce more hormone, but too much or too little TSH does not change how you feel.  There is only one way to alleviate symptoms, and that is by manipulating the actual thyroid hormones, FT3 and FT4.

This is not a matter of opinion, but a matter of fact.  

Let me use myself as an example.  My TSH is about 20 due to a pituitary issue.  However, I am euthyroid (neither hypo nor hyper) since my FT3 and FT4 are in reference range and I am asymptomatic.  When my FT3 and FT4 were below range, I was very hypo.  Getting my FT3 and FT4 to optimal levels for me relieved all my symptoms.  My TSH does not in any way affect how I feel.

You're right, differing opinions are what this forum is all about.  However, so is correcting misinformation and maintaining quality in what we write.  I don't think you really understand the role of TSH in the big picture.

[gimel]

Sorry, but since FT3 and FT4 are the biologically active thyroid hormones that affect metabolism and many other body functions (symptoms), I cannot agree that the same levels of FT3 and FT4 can be the cause of  a patient being hypo one time and overmedicated and hyper another time.   I think that such a result can only be caused by other variables that you haven't identified, such as adrenal problems, or sensitivity to medication, or starting on too high of a dose of medication, etc.   And it certainly is not due to TSH, since TSH does not affect metabolism and other body functions affected by FT3 and FT4.

[6hashi]

FT3 and FT4 in patient with balanced gland can be the same as those when he was hypo and the same as when he was overmedicated and hyper !!

any way ,having different point of views enriches the forum,so I am happy that there are others who think differently !

[gimel]

I'm very glad you responded to my post in a positive manner.  We are all learning here, every day, so I'm very happy to consider and discuss different opinions.  I wold like to try and reach agreement with you about the value of TSH, when medicating a thyroid patient.  This is important because if we give members different advice, then sometimes that can confuse them, at a time when they are trying to understand what to do to help them feel better.   So let me try to clarify some of my core beliefs.

First, symptoms are all important.  They are the reason we go to the doctor in the first place.  Any treatment that does not relieve symptoms is unsuccessful.  

Second would be that symptoms have been shown to correlate best with levels of the biologically active thyroid hormones, which are FT3 and FT4.  In fact, the very best correlation was established to be with FT3, which makes sense, because FT3 is at least four times as biologically active as FT4.  Symptoms correlate very poorly with levels of TSH.

So, doesn't it make sense that to alleviate symptoms, we should be the most concerned about the level of FT3, and then the level of FT4?  If you would agree with that, then the way we have to go about doing that is by prescribing medication to change the levels of FT3 and FT4.  If the patient's body converts T4 to T3 adequately, then a T4 med may by perfectly adequate.  If there is an imbalance of FT4 to FT3, then it may be necessary to also include a medication that includes T3.

The  amount and type of medication that is required to alleviate symptoms will, of course result in a corresponding level of FT3 and FT4.  So with medication you can manipulate the levels of FT3 and FT4 to whatever is required.  And yes, the reaction to meds differs among patients, but the levels can be still be adjusted to the desired levels by adjusting dosage.  

Since the TSH output from the pituitary is dependent upon the levels of FT3 and FT4 in the blood, this means that TSH is the dependent variable.  You cannot adjust TSH directly.  TSH changes in response to  the levels of FT3 and FT4 that are created by the amount and type of medication given.  

So if  given levels of FT3 and FT4 are required to alleviate symptoms, then that automatically gives you a TSH result.  If that TSH falls below the ref. range, so what?  If symptoms are alleviated and FT3 and FT4 are within the "normal" limits, why should we be concerned about TSH at all at that point.  Under those conditions I certainly would not recommend that medication should be lowered just to bring TSH within its "normal" range.  

So that's basically why I firmly believe that when a patient is on medication, TSH becomes relatively unimportant.  To me it is certainly not important enough to affect decisions about medication dosage.   And , by the way, I know this is only a sample of one, but my TSH has been less than .05 for well over 25 years and I still  had lingering hypo symptoms until I learned about the vital importance of FT3 and was able to get my medication changed to include a source of T3.  I'm still making minor changes, but my FT3 level has already gone up from 2.6 to 3.5 (range was 2.3 - 4.2), and I'm feeling the best ever.

[6hashi]

You are one of the most important members in this forum ,further more ,your name appeared on the homor board !

If TSH is inadequat ,then why to suppress the gland one need to have a TSH <0.01 ,I would suggest instead to add T4 and T3 till they both in the upper part of the range !

I know about cases in which the FT3 and FT4 when there gland is balanced are the same as when being diagnosed as primarily hypo ,however ,the reduced the TSH and have the tens of symptos gone !

You can't direct the FT3 and FT4 alone ,since each body have certain valuse for these ,toward which it pushs ,even if you add more and more or if you are  hypo !!

that said ,I do agree to that  that getting TSH in normal range is not enough.
Some times there is a need for adding T3 also !

all the best to you gimel ,

[gimel]

I expect that your comment was really directed to me, so let me just say that when you want to disagree with something you need to get your facts straight.  First , I always say what I stated in paragraph one, above.  Namely, that relief of symptoms is all important.  And that frequently, this necessitates that FT3 is adjusted into the upper part of its range and that FT4 is adjusted to at least the midpoint of its range.  Note, that I said frequently.  I have never said that the higher levels apply for everyone.  Medication adequate to relieve symptoms should apply to everyone, however.

In addition, apparently you have a long standing belief in the TSH test.  I really don't understand why this is so, since TSH is only a hypothalamus/pituitary reaction to the levels of thyroid hormone in the blood.  Doctors, and you, tend to believe that it has an infallible correlation with thyroid hormone levels, yet scientific studies that you love so well have shown this is not the case.  Scientific studies have also shown that TSH does not correlate very well at all with hypo symptoms.  In fact, by far the best correlation with hypo symptoms is with FT3.  So rather than rely on TSH and assume that it is providing accurate information about the necessary levels of thyroid hormone, and symptoms, why not just test and adjust  FT3 and FT4,  since they correlate best with hypo symptoms.  

Further, if you think of the logic of it, since TSH is a dependent variable (dependent on the hypothalamus/pituitary response to actual thyroid hormone levels), then you can;t adjust each independently.  If you adjust FT3 and FT4 levels, you get a resultant level of TSH.  If you try to control TSH level, then that dictates some level of FT3 and FT4., that may not be adequate to alleviate symptoms.  So why is that the preferred approach?  
Such a treatment protocol  probably leaves you where you have been for some time as I recall -- reluctant to turn loose of TSH and adequately adjust your FT3 level enough to alleviate your symptoms.