I got RX for Primary Addison's 2 months ago. Classic symptom's (which I had all of them) was low blood sodium (and falling), unexplained weight loss (like a pound a day), darkening skin color (I had people asking if I was getting darker), Bowl issues, hypo episodes (or so I thought as last one I laid on the floor for 2 hours and could hardly move). My blood ACTH was more than the machine could measure (several 100 times the normal level) and my cortisol stimulation test hardly caused a cortisol increase. A single blood test is all that is needed to rule out Addison's however it takes a few tests to determine which kind of Addison's someone may have.