Addison disease (hypoadrenocorticism) results from the lack of glucocorticoids, mineralocorticoids, or both. Isolated aldosterone insufficiency appears to be very rare, whereas isolated glucocorticoid insufficiency is likely underdiagnosed given the lack of electrolyte abnormalities. The clinical signs of hypoadrenocorticism are often vague, may wax and wane over time, are rarely pathognomonic, and may be present for days, weeks, or months before diagnosis. Diagnosis depends on an accurate history, physical examination, and screening laboratory tests (CBC, chemistry panel, urinalysis). Confirmation requires adrenal function testing using the ACTH stimulation test. Treatment is highly successful but often lifelong (see: Wikipedia).