Graves vs Hashimoto, differential diagnosis

[ar1281a]

I've found so much wisdom on this forum, so I'm hoping to shed some light on the following: I was diagnosed with Graves disease about 10 years ago. I was severely hyperthyroid (TSH undetectable and high FT3 & FT4) with active antibodies (TPO and TSI).  I decided to take an anti-thriroid med rather than burning my thyroid with RAI. Few years later, I went hypo, and was put on synthroid. This lasted a couple of years, and then I went hyper again. After this, my thyroid went "normal," and I thought I'd had achieved remission. Three years, my hyperthyroidsm returned and I was put on tapazole again, it took about six months to bring it under control. I was tested again for antibodies and tested positive for TPO, TSI, TBII. At this point, my endo is advicing me to do something about my thyroid as she believes I won't be able to achieve remission again.

Now, this week I went to see a new allergist/immunologist (I have bad allergies as well that I've always suspected are related to my immune problems) and he examined my thyroid and told me that he believed I have hashimoto's and not graves. He was going to run some tests.

I've always associated hashi with hypo but read online that it can also present as hyper and go back and forward between hyper/hypo.

What's the differential diagnosis for these two diseases? how can I know for sure if it's one or the other one? it'd certainly change my approach and next steps.

Thanks

[ar1281a]

Thanks for the reply, yes, the TSI are above range at 2,0 (0-1.3) and TPO at 4.9 (0-8.9)

[LazyMoose]

If you tested positive (over the range) for TSI then you for sure have Graves. But you said 'active antibodies'. This needs to be clarified. i know that with TPO there is a limit, over this is a concern. Under, but still some antibodies present, is OK.

Very, very few do have both - its possible.