Very low TSH but normal t4 levels

[kjames13]

Since December of 2007, I have been trying to find out what is going on with me.  I have a nodule on my right thyroid gland...they did ultrasound, normal, a biopsy, normal, and a thyroid uptake scan, normal, but I still have the nodule, and they can't figure out what is going on.  Both blood tests I have recieved, my Free T4 has come back normal, but my TSH levels are very very low, almost non-existant.  The one taken in December my Free T4 was 0.98NG/DL and my TSH was <0.06L mIU/L.  My regular physician thinks it may have something to do with my pituitary gland, because she said for the TSH to be that low, my T4 levels should be off the chart high.  Does anyone have any suggestions?

Kari

[teeweetwirler]

A related discussion, low free thyroxine level normal to low tsh level was started.

[Smilerdeb]

My last labs were :

FT4 14.3 (10.0-19.0)
FT3 5.8 (3.5 - 6.5)
TSH 0.08 (0.50 -4.00)

And I have Graves disease diagnosed last year with Graves Antibodies.
My highest FT4 has been 29.1
and my highest FT3 has been 17.9

I have been taking antithyroid meds for over a year now but still no go...the levels fluctuate so fast that its hard to keep up with them and now I am not tolerating the meds too well as well as high liver enzymes.
Take Dr. Lupos advise and get the Graves antibodies tests done.

Take Care :)

[Mark Lupo, M.D.]

It's either a hot (overactive) nodule or Graves.  The scan should have shown a hot nodule, so it's likely Graves.  The other less likely option is pituitary.  Would re-evaluate the scan to see what it showed.  Would test TSI and TBII (Graves antibodies) and check prolactin to screen for pituitary.  Also need a T3 level.  This looks like subclinical hyperthyroidism.

[cpar1]

I had the same thing, but I was tested for pituitary disease, and it came back negative.  They are treating me for Graves Disease even though my T4 is not high.  I must admit I am feeling much better.  Hope you get a solution soon!