What's the difference between primary and secondary addison's disease?

Source of problem: Addison's disease is a failure of your adrenal glands to make the hormones they usually make. In primary disease it is the adrenals themselves that are problematic, whereas in secondary disease it is the pituitary gland, which produces a signal which stimates (desmopressin) the adrenals to do what they do, that is the source of the problem. The hormones likely to be deficient can be very different in the two.

1ry starts in gland: Primary addison's originates in the adrenal gland for diverse reasons, autoimmune (self destruction by auto antibodies) or after an infection (e.G tb), invasion by cancer or hemorrhage into the gland, while in the secondary type the gland itself is healthy but the pituitary gland (the maestro of endocrine glands) isn't working so other endocrine glands won't function probably.