What do I tell my vet?

I think my dog has hypothyroidism, and we are going to the vet soon. I want her to get tested for it, so do I just say I want her tested for hypothyroidism or what? (I have extreme shyness and I'm afraid he will think I don't have a clue what I'm saying or something...I just want to make sure I say the right thing...)
but I've done a lot of research and this website sounds like it is describing my dog! almost exactly!

http://www.lloydinc.com/pdfs/Does_My_Dog_Have_a_Thyroid_Problem.pdf