Adrenal insufficiency is a rare disorder, usually with gradually evolving clinical symptoms and signs. Occasionally, an acute adrenal insufficiency crisis can become a life-threatening condition because of acute interruption of a normal or hyperfunctioning adrenal or pituitary gland or sudden interruption of a adrenal replacement therapy. Acute stress situations can aggravate the symptomatology. A simple strategy or diagnostic screening and early intervention with sodium chloride-containing fluids and hydrocortisone should be widely implemented for cases with suspicion of an acute Addison disease crisis. In contrast, the chronic replacement dosage for patients with adrenal insufficiency should be as low as possible with clear instructions for dosage adjustments in case of stress or acute emergencies.