I have a lot of symptoms of a slow thyroid, but every test I take comes out negative. What do I do next?

I have a family history of slow thyroids and, frankly, thyroids that quit. My metabolism is SLOW. I’ve had depression and a lot of other symptoms. My mom’s thyroid just gave out and they’ve put her on replacement thyroid hormone. She’s lost a ton of weight and she’s much happier.

I’ve taken every blood test that I know to ask for. They agree my thyroid is on the sluggish side, but that’s it. Should I see an endocrinologist? What do I do next?