Adrenal crisis is a medical emergency, which requires quick, accurate diagnosis and the implementation of adequate treatment. It usually occurs in patients taking glucocorticoid therapy due to chronic adrenal insufficiency in conditions that demand increased glucocorticoids, such as infection, trauma, surgery, myocardial infarction, stroke, exercise or acute stress. The disease follows a course of shock that does not respond to catecholamines. Prodromal symptoms include decreased appetite, nausea, vomiting, abdominal pain, joint or muscle pain, and fatigue. This is followed by fluctuating consciousness, as well as reduced blood pressure and tachycardia, which are symptoms of shock. These symptoms result from the following metabolic disorders: hyponatremia, hyperkalaemia, hypoglycaemia and mild hypercalcemia. Due to the absence of characteristic symptoms in adrenal crisis, the basis for correct diagnosis in a prehospital setting is a carefully collected medical history, followed by a detailed physical examination that should pay particular attention to discoloration of the skin (so-called melasma suprarenale) that is not exposed to light: the hands (especially creases), elbows, areolae, scars and buccal mucosa, which is one of the symptoms of primary adrenal insufficiency (Addison’s disease). The therapeutic approach consists in the administration of intravenous hydrocortisone (to moderate cortisol deficiency), modifying fluid and electrolyte imbalances and abnormalities of acid-base balance, and treating the disease that has led to decompensation of the patient’s clinical condition, which in many cases is an infection. Adrenal crisis left untreated leads to patient death.