Adrenocortical insufficiency from primary causes (autoimmune condition, bilateral hemorrhage, TB, fungal infection) or secondary causes (ACTH suppression by iatrogenic corticosteroid administration). Both causes result in cortisol deficiency with hypoglycemia, hypotension, anorexia, vomiting, atrophic gastritis, weight loss, malaise, abdominal pain, inability to react to stress, and sometimes skin hyperpigmentation. With primary causes only, aldosterone deficiency leads to hyperkalemia, hyponatremia, volume depletion, acidosis, and azotemia. Patients undergoing surgery or invasive procedures must receive stress-dose steroids (typically hydrocortisone 100-300 mg perioperatively, tapered over the following 1-5 days).