Nikki,

The treatment would be the same for Primary and Secondary Addison patients but I can see why you would want to know. If it's secondary, you could watch for other hormones that would be affected by hypopituitarism. Plus, the should probably check your Pituitary for anything unusual in a visual scan.

If you can get access to your ACTH stimulation test numbers, that would tell you instantly if it's secondary or primary. With Primary Addison's, the gland doesn't produce more Cortisol when it's given the synthetic stimuli. Your baseline Cortisol level will be the same low number 30 minutes and 60 minutes after the injection of ACTH.
With Secondary, your baseline number will be low but will triple and quadruple your Cortisol output. A normal person's ACTH doubles in the 60 minute time-frame. A secondary Addison's will do a lot more than double. That means the gland itself works fine but it's not functioning normally due to lack of trigger hormones.

I had the same thing. I had an ACTH stim test and failed with flying colors. both values close to zero. After MUCH work up and $$$ (and switching to an older endocrinologist who has "Seen" it, b/c addison's is rare) i have been formally diagnosed with primary addison's caused by lymphocytic hypophysitis. you can google that to read. i have a history of a major postpartum hemorrhage. this is what he attributes it to. i have been diagnosed a year. i am SO thankful to be alive, but SO discouraged, as it has been hard to get control of and figure out what medication combinations work best., then how to recognize and treat impending crisis.. i take hydrocortisone daily in divided doses and florinef. i have MAJOR problems in particular with my legs. they hurt all the time and the back of my leg/ muscles are very weak. this is so discouraging bc it affects my quality of life so much. i have seven children and a physician husband who works much....the load is heavy and i don't seem to be able to keep up anymore.