Comprehensive diagnostic testing enables accurate determination of adrenal hormone deficiencies and their underlying causes, thus providing a basis for individualised treatment considerations. The current use of modern methods for adrenal hormone analysis, testing for the ACTH stimulation response (a biological marker of normal adrenal function), antibody evaluation, and imaging studies offers greater opportunities to detect and manage adrenal insufficiency in earlier stages, which then decreases the incidence of adrenal crisis and improves long-term health outcome measures for endocrine and metabolic function.