My diagnosis was obvious in hindsight (walking around the roof of an 8 story building among other things) but was about 7 years after the onset of my BP. I asked for a referral to a pdoc, got asked a heap of questions, got diagnosed and then put on meds. It took a long time to get the right med combo, but now things are good.
Here is a good website to take an online test: Black dog institute self test