Adrenal Insufficiency

Two questions organize every adrenal insufficiency encounter: where has the hypothalamic-pituitary-adrenal axis failed, and is the patient in crisis? The first separates primary cortical disease from central or glucocorticoid-induced suppression. Primary disease usually removes aldosterone as well as cortisol; central disease generally preserves aldosterone because the renin-angiotensin-aldosterone system, not ACTH, drives its secretion. That distinction predicts the bedside pattern and determines whether fludrocortisone is needed. The second question is time-sensitive. A patient with vomiting, hypotension, weakness, or altered mentation after infection, gastrointestinal illness, surgery, trauma, missed doses, or abrupt glucocorticoid withdrawal may be in adrenal crisis. Hydrocortisone and fluid resuscitation must not wait for confirmatory testing. Stable patients can then be localized with ACTH, electrolytes, and stimulation testing, while long-term care combines replacement, sick-day planning, and monitoring.