Hashimoto's hypothyroid, that is now suddenly hyperthyroid.

[lurasmurf]

Hi there,
I was originally diagnosed with Hashimoto's in 2000. (The antibodies test was positive). With a lot of tinkering, my medication level became stable at 237 mcg, and have been so for at least 2 years.

Late March I noticed a nodule growing in the right side of my thyroid. My physician ordered an ultrasound, and noticed a sizable nodule there. She also took my TSH and T4's. They are now as follows:

TSH < 0.1 Milli Intl-units/L
T4 Free 1.87 ng/dL

She is not sure why I am suddenly so over medicated.
My question is, how is it I am now hyperthyroid, and do you think the nodule is associated with it?
And what tests would you suggest in figuring out what's next?

Thanks
Lura

[Mark Lupo, M.D.]

If the nodule is not clearly a "hot" nodule, it needs FNA biopsy.

[Mark Lupo, M.D.]

The nodule may be over-producing thyroid hormone.  An I-123 uptake/scan can be done to make this diagnosis -- you do not need to stop the lveothyroxine for the scan to make this determination (despite what they may tell you)  - but you do need to lower the dose to try to bring the TSH up a bit...