T4 conversion to T3

[grantj]

Upon reading, research and lab results, I am thinking that the nature of my thyroid challenges lie in lack of conversion (and, yes, I realize I could be totally off base).  I have normal TSH (2.54), low normal free T4 (1.02) and very low (compared to what I need to function optimally) free T3 (2.4).  Does this sound like a conversion issue with the fact that my TSH isn't really high and T4 is ok.  I am so wanting to understand all of this; I respond very well to Armour for the most part, developed terrible flu like symptoms, depression on Synthroid.  Opinions?  Thanks, Debbie J

[Barb135]

FTB4 is no longer active on the forum... are you asking a question?

Your FT4 is at 75% of the range and your FT3 is only at 37%.  Rule of thumb (where most of us fee best) is for FT4 to be around mid range and for FT3 to be mid to upper range.  Your FT4 is higher than it needs to be and your FT3 could stand a boost up, if you have hypo symptoms.

Since you're already on Synthroid, the easiest method would be to add cytomel or its generic counterpart, liothyronine.  Typically, the T4 med is decreased by 20-25 mcg for every 5 mcg of T3 added, which could be about right, since your FT4 is already higher than necessary.

Do you have symptoms of hypo?  What's your current dose of Synthroid?

[jmnamee]

Free T3:  3.0; range 2.3 - 4.2
Free T4:  1.64; range 0.73 - 1.95
TSH <0.1; range 0.5 - 4.7

I have had my thyroid removed and am currently taking Synthroid.

[grantj]

I received an email asking me to select a Best Answer to these responses, but cannot figure out how to do this?  Help...

[stella5349]

absolutely. Many optimal thyroid patients are shocked on where their TSH falls when they feel their best and that can become another "head-game" the doctors have trouble with.

A doctor who sees a TSH low. many feel that means the patient is too high on thryoid meds and force the patient to drop dosages.

If the monitor of Free T labs is looked at with symptoms and then lastly compared with the TSH - doctors and patients can find a suitable dosage to be at to feel good- vs - just being leveled on a dosaged strickly based only on a TSH lab.

Good Luck.

[Barb135]

Jumping in with gimel -- my TSH has been < 0.01 for over 3 yrs, but my actual thyroid levels did not correspond.......  My doctor (at one time) kept lowering my dose, and kept me sick for a long time........  My current pcp keeps wanting to lower my dosage because of TSH - I let him once; never again........ my endo, who understands that TSH may be suppressed, and myself, decide the dosage of my thyroid med.

[gimel]

Just want to supplement the good info here already.  Don't be concerned if your TSH drops below the lower range limit.  That does not mean that you have become hyper, unless you do have hyper symptoms caused by excessive levels of FT3 and FT4, which is unlikely from your last test results.  

Patients frequently find that their TSH is suppressed when taking significant dosages of thyroid meds, adequate to relieve symptoms.  Symptom relief is all important, not test results.  Test results are valuable mainly as an indicator during diagnosis and then to monitor changes as meds are increased toward symptom relief.  

For example my TSH has been about .05 for well over 25 years without ever having hyper symptoms.  Couldn't tell you how many times doctors wanted to reduce my meds because supposedly I was hyper.    NOT!

[grantj]

Stella, you are sweet!  Thank you.  Yeah, I think back to when I felt my absolute best and it was when my T3 was near 3.15 and my TSH was .32 or so (don't have them in front
of me).  For some reason, I did not stay that way for long though even with same dose?  It fell a bit from there but I remained feeling pretty decent for the most part.  No more playing around for me!  I find all this fascinating and am so glad to have finally discovered this forum.  What I've found is that there is such a fine line to feeling really great to feeling either symptoms of too much or too little (symptoms are very similar for me in both).

[stella5349]

I can say something short and sweet:

You need thyroid meds. :)

The conversion chart that was discussed above would be helpful in knowing about conversion abnormal levels but your labs classically show a sign of undermedicated... period.

You need thyroid meds. :)

Stay on the current dose. Test in 3 weeks and I'm 90% sure you will need an increase.

Keep in mind - any thyroid meds with built in T3 or even synthetic T3 alone - should suppress the TSH to almost zero exsistance. You have a long way for that to happen and most T3/T4 combo patients aren't feeling their best until the T3 and T4 are high on the reference.. ( FT3 - high part - FT4 - mid to high) and the TSH is 99% of the time suppressed to .80 or even 0.008.

You got room there.

Stay on the meds.

[grantj]

Thanks, my labs represent me being off Armour for three weeks; so pure levels on my own, non medicated.  Quick overview:  I was on Metformin prior for what turned out to be a mis diagnosis of PCOS (4/08) (about a year later I was diagnosed with hypo, went on Armour, this was 3/09); had a number of Dr.'s dispute this diagnosis (PCOS) over time, and was finally weaned off Metformin mid Feb per my OBGYN.  Over the next week (s), I gradually took on feelings of too much thyroid med leaving me with the conclusion (stupid on my part, like I am a Dr. or something!) that I never really needed thyroid med to begin with, it was the Metformin that was causing hypo.  With me being very thin and fit, the hypo thing seemed odd, even to my primary doc. (not impossible, but odd).  While I quickly began noticing strong signs of hypo again, I was convinced that my body was just trying to adjust to this and I would be back up on my own shortly.  After three weeks of pure hell, I got tested (see above results) and I am back on Armour.  I plan to work very closely with my doc from here on out now believing that I really do have hypo; guess I was in denial or something.  I have been back on meds since Monday and already starting to perk up to my normal self.  Dosing of this drug and times to take it were/are my primary challenge; it would have been so nice not to need anything to feel great.  thnx

[Barb135]

You might have a conversion issue; however, both your FT3 and FT4 are too low in their ranges, AND your TSH is also relatively high.  Seems like a simple dosage increase might be in order.

[goolarra]

Were you on Armour just before these labs?  

Armour contains both T4 and T3.  It's T3 content is relatively high, so it should be addressing any conversion issue you might have.

It looks to me like you need a meds increase as there is ample room in all your labs for improvement.

[FTB4]

See results in message format. FTB4

[grantj]

Free T3 is 2.4 (2.3-4.2 range), Free T4 is 1.02 (.89-1.76 range) and TSH is 2.541 (.5-4.78 range).  Thanks!!  Debbie

[FTB4]

It is possible to have a conversion problem, that is my issue, so my MD just took me off of Synthroid and put me on Armour three weeks ago, There is a math formula using your levels and reference ranges to determine if you have a conversion problem. If you want to post Free T3 and Free T4 with the reference ranges, I can figure it out and let you know.
FTB4