Free T4 or T4?

[PaintingCate]

When a doctor orders a thyroid panel to check levels do they have to request a T4 level separate or is it included in a standard thyroid panel?  I got my lab results today and comparing them to other results I noticed I didn't have a FREE T4 number before only the T4 (well wasn't given one anyways).   What makes them different and can your FREE T4 be in normal range and your T4 be too high?  What's the one to look at when dealing with Graves'?  I'm feeling hyper thyroid for sure and know my TSH is low again, but the FREE T4 is normal.  If they aren't different, what does it mean when your TSH is low but all other levels are normal?

Result Today:

Free T4 8.6
(range 4.5-12.0)

T3 2.9
(range 1.2-4.9)

T3 Uptake 31.4%
(range 24-39%)

TSH 0.176
(range 0.45-4.5)

My TSH was .96 last time and my T4 was right in the middle, but I was still feeling tired and not myself.  So my synthroid was increased from 125 mcg to 137 mcg to try and increase my TSH level.  After the increase I started feeling better about 6 weeks in but now I'm feeling hyper thyroid after about 3 months.  Thanks for any info :)

[Smilerdeb]

Your Doc shouldve known NOT to increase you with a tsh that low and especially more so after a history of thyroid storm.
Your Doc should be taking 'baby steps' with your meds and personally I feel he is going 'too hard' at it.
Taking baby steps and going slower in smaller doses will balance out the levels slowly instead of taking you to 'hyper' and then having to 'come down' and decrease.
Just my opinion.

[PaintingCate]

I do have graves' disease, I was diagnosed May of 2008 after the hyper thyroid symptoms landed me in the emergency room with a heart rate of 165 bpm when resting and uncontrollable hand tremors.  I had a goiter the size of a grapefruit and growing daily when it was removed a month later in July of 2008.  I'm having hyper thyroid symptoms again on synthroid and was wondering the difference between free T4 and just T4.  I thought for a moment that if your T4 and T3 are normal but your TSH is low if you could have a problem with your pituitary gland or something.  The samples were tested by different labs too so I still don't know what the difference is.  

Thank you for the information on the synthroid, I do feel I'm over medicated and they are working at adjusting that.  I don't know how I didn't realize or put together that more synthroid would make my TSH go down - man I feel dumb now!  I know that, how did I not think about that?!  Wow what a bad brain moment there!  I felt awesome for about 10 days after I started the synthroid for the first time after surgery and that was after taking it for 6 wks on the 125 mcg dose - and couldn't believe I could still feel that good.  Then just as soon as it started...gone!  That must of been the level I needed, which would make even 125 mcg too high of a dose.  Remembering that I'll mention that to him when I go in this next week. That helps a lot and I appreciate your time and bringing that to my attention.  Frustrating to think that the Doc knows that, why didn't he lower the dose instead of increasing?  Who knows, at least now I know-for that I'm grateful!

Thanks,
Catharina

[Totie]

I did not understand the increase in the dosage either. Your TSH was .96, your dosage should had stayed the same or decreased, not increased, which is what is throwing you into hyper stage. Call your doctor, you are being over medicated.

[goolarra]

I don't know that there is such a thing as a "standard thyroid panel".  The three important tests for initial diagnosis and medication adjustment are TSH, FT3 and FT4.  Mine are all ordered separately (same blood draw).

Free T4 (FT4) tells you how much T4 is actually available to your cells.  A total T4 (TT4) tells you how much total T4 is in your blood...some of it is chemically bound and therefore unavailable.  So, FT4 gives more (better) information.

You have been diagnosed as HYPOthyroid.  Therefore, you do not have Grave's disease.  Grave's disease is associated with HYPERthyroidism.  If you feel hyper because of excessive meds, that does not mean you have Grave's.  Grave's is an autoimmune disease.

If your Synthroid was increased from 125 to 137, we would expect your TSH to DECREASE, which it did.  TSH is counterintuitive - as it goes up, you move toward hypo (low) and as it goes down, you move toward hyper (high).

It looks like you're just a tad overmedicated.  Your TSH is quite low.  You might try taking a 125 every other day, alternating with a 137 the other days.  Ask your doctor about this first, of course.  If you're really feeling very hyper, he might want you to back off to 125 for a few days to a week, and then start alternating 125/137.

Hope this helps clarify.