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Optimal levels of Free T3 and Free T4 post TT
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Optimal levels of Free T3 and Free T4 post TT

Hello All!
It's been a long time since I've posted, but needed to get some advice and answers some questions from all of the knowledgable people on this thread.  I had a total thyroidectomy in 5/2007 secondary to thyroid nodules, hypothyroidism- dx after TT, micropapillary carcinoma.  Now trying to keep my TSH between .1 and .5, which seems a little too low for my body to handle.-fatigued, tire easily, oily skin, increased appetite (eating more, but not gaining weight), sleep disturbances...on T4 meds only for past 6 years (pre and post surgery). Finally a doctor agreed to test my Free T3 level.  I see her next week and wanted to go in armed with information.
Current levels:
TSH   0.112 (L) norms are: (0.3-5.0)  so technically in "plan" for where they want to keep me, but I'm not "feeling" well there.
Free T4  1.36 (0.76-2.12 ng/dL)
Free T3  280  no reference range given (other sites show 230-612 or 420)...
1)  because the Free T3 is technically lower than the T4 in the optimal range, does this look like I am not converting T4 to T3?
Total Chol-248 (0-200), HDL (good chol) 61 (45-86);  and LDL (bad chol) 165 (0-130)  Chol/HDL 4.1
Cholesterol has only been an issue since dealing with hypothyroidism.  
2)  Most recent recommendation is change diet and increase exercise, but I thought that was related to the good chol-any knowledge of T3 helping to lower cholesterol.

Any thoughts-suggestions, welcome.
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7 Comments Post a Comment
Avatar f tn
The levels of FT3, FT4 and TSH are all a matter of where YOU feel comfortable.  Doctors have "goals" (e.g. TSH form .0.1 to 0.5), but those may not be realistic for us as individuals.  What good is it to reach the goal, but still not feel well?  I hope your new doctor treats based on symptoms.  Your symptoms sound hyper (overmedicated).  Your FT3 (is that an FT3 or TT3?) and FT4 are still low in the ranges, but some of us are comfortable there (I'm one of them).

I am attaching a blurb I wrote about how reference ranges should be used to help us feel neither hypo nor hyper.  Disclaimer:  not a doctor, just my opinion.  Hope this sheds some light.  Although the example is FT4, the theory applies equally to FT3 and TSH.  Also, the example refers to undertreatment, but also applies to ovemedication.

Proper Use of Reference Ranges in Treating Hypothyroidism:  Some Ideas to Discuss with your Doctor

Many hypo patients or undiagnosed hypo patients have an array of hypo symptoms, yet their lab work (free T3, free T4 and TSH) indicate that they are within the reference ranges that doctors erroneously refer to as “normal”.  TSH is often high in the range (or maybe even above the range according to the latest standards of 0.3-3.0 which many labs and doctors still refuse use) and FT3 and/or FT4 are low in their ranges.  Many doctors think that if labs are anywhere within ranges, their job is done...patient is no longer hypo, any remaining symptoms are not thyroid related, patient is fat and lazy.  NOT TRUE.  

Please see illustration below.  Each of us has a personal reference range within the population reference range at which we are euthyroid (neither hypo nor hyper).  A shift in lab values of the individual outside of his or her individual reference range, but still within the population reference range, is not normal for that individual.  Many don't feel well until FT3 and FT4 are in the upper half of the ranges.  After all, the population ranges of FT3 and FT4 are statistically determined distributions of patient results; by definition, approximately half the population will be euthyroid in the top half of the range and approximately half in the bottom.  If you are one of the people whose personal range must be in the top of the ranges, and your doctor won’t treat you or won’t fine-tune your medication when your results are in the bottom of the range, you are left hypo.  Your doctor may tell you your labs are "normal", but they are NOT “normal” for you.

Reference ranges of test results do not imply that everyone is going to be well as long as they are anywhere in the ranges.  The ranges are broad (e.g. 0.6-2.0 for FT4).  If your personal FT4 reference range was 1.6-1.8 when your thyroid was functioning properly, does it really make any logical sense at all that now that you are on replacement hormones, you should feel comfortable with an FT4 of 1.0?  No, it doesn't.  We all have a set point that is optimal for us...doctors should be finding it and adjusting medication to it.

If labs are within ranges, it's time for fine-tuning (or initiating a low dose trial)...increasing meds slightly if hypo symptoms are still present.  This will move FT3 and FT4 up in the range and alleviate symptoms…that’s the goal.  The ranges define the universe in which we can freely adjust medication; its entire breadth from lower limit to upper should be used for this purpose.  The patient will still be in the reference ranges, but he or she will no longer be symptomatic.  

                Current                      Reference
                  Level                            Range
0.6               1.0                       [1.6……1.8]          2.0
|-----------------Population Reference Range-------------------|

With an FT4 of 1.0, patient is still hypo according to his/her personal reference range.
Avatar f tn
Thanks goolarra!  I had noticed your "blurb" prior to posting, just wanted to get an idea of thoughts on my Free T3 level, as it was the first time they agreed to do it.  My total T3 was 1.10 (.60-1.81)
free T3 280 with no ref indicated

Had I seen somewhere also that you were from PA?  closer to Pgh or Philly?--my last two endos have left the practice, haven't seen this new one yet-I'm in the Pgh region.
Avatar f tn
It's kind of difficult to comment without a reference range on the FT3.  The ones you did get (230-612 or 420), that's quite a spread.  If it's 612, the range is almost twice as broad as if it's 420.  However, I don't think conversion is the issue.  Your FT4 is barely into the middle third of the range, and your FT3 (assuming 230-420) is in the top of the bottom third.  So, they are consistent with each other.  

Do you agree with me that your symptoms seem hyper?  My gut feeling is that you are one of those people who are comfortable in the lower end of the range.  Although I wrote about people who are not comfortable until they are in the upper end of the range (because they are left under- or un-medicated so often), there are also many of us who ARE comfortable lower in the range.  Your TSH is a bit on the low side, indicating that your pituitary also thinks you're overmedicated.

I'm in Oregon!  
Avatar m tn
I have had thyroid issues for over 12 years now.  My treatment plan for that time consisted of taking synthroid .112 for most of the 12 years, keeping TSH around 1.2.  After three babies and getting older (39) I started feeling tired, constipated, and very FOGGY thinking.  Would go into doc and he would do blood tests and say your fine in your current dose and you are in rage for TSH.  Started taking ADD meds because it was so frustrating.  

Recently saw a doctor who checked all blood work and lab results for thryoid.  She said she thought my t4 was not converting to enough t3 and supplemented t3 to synthroid.  We are still tinkering with the dose but I cut synthroid in 1/2 and added 10 micrograms of cytomel split in 5 in am and 5 around 2.  May even try 4 doses through the day.  

The results were immediate and I noticed that I was less impulsive, less irratable, drank less within the week.  I hope this helps you to try a t3 along with t4 meds.  I am finding more sites that are helping me with information.  Please consider trying t3 but be sure to cut your dose of synthroid in half.  We did not start doing this as I started with .88 and 10 mcg of t3.  Hair was falling out, did not feel good.  Now at 1/2 of original dose of t4 with t3 I feel much better.  Will see in 6 weeks what the labs show.  Maybe even just 5 mgc would be helpful.  

Good luck to you.  
Avatar m tn
Try going to for more info and things you can print and take to your doctor for information to prescribe the t3.
Avatar n tn
I had a TT july/10 after TT took 100mcg Eltroxin
RAI ablation Nov/10
TSH levels preablation 46.24
T4 18.1
T3 --
Post ablation
TSH 53.26
T4  18.1
T3   5.0
Eltroxin increased to 150 mcg
Dec 15/10
TSH  0.05
T4  22.5
T3  6.3
Eltroxin reduced to 100 mcg
Dec 30/10
TSH  0.02
T4  21.5
T3  6.5
Post ablation scan showed low grade foci activity in thyroid bed and two new foci of activity inferior to the tyroid bed
Now I am freezing all the time, sweating profusily in my sleep and very tired..what is normal
Avatar m tn
You will gets lots more attention and response if you start a new thread by clicking on the Post a Question button at the top of page.  Also, when you do that please include with the T3, T4 and TSH test results, the reference ranges shown on the lab report. These ranges vary from lab to lab and need to be taken from your own lab.
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