Emergency medicine physicians should be able to identify and treat patients whose clinical presentations, including key historical, physical examination, and laboratory findings are consistent with diagnoses of primary, secondary, and tertiary adrenal insufficiency, adrenal crisis, and pheochromocytoma. Failure to make a timely diagnosis leads to increased morbidity and mortality. As great mimickers, adrenal emergencies often present with a constellation of nonspecific signs and symptoms that can lead even the most diligent emergency physician astray. The emergency physician must include adrenal emergencies in the differential diagnosis when encountering such clinical pictures.