Snapshot A 27-year-old, 2-week post-partum woman presents to the clinic complaining of weakness, fatigue, and inability to produce milk. Her pregnancy was unremarkable but she suffered significant blood loss during delivery. She reports that the first few days she was producing enough milk for her baby but the supply subsequently decreased. Laboratory testing demonstrates low serum cortisol and plasma ACTH levels. (Sheehan syndrome) Introduction A disorder characterized by decreased secretion of corticotropin (ACTH) by the pituitary gland leading to adrenal insufficiency (e.g., low levels of cortisol). the adrenal glands are intrinsically normal but may be atrophic because of chronic ACTH deficiency Epidemiology Risk factors exogenous steroid use traumatic brain injury chronic opioid use ETIOLOGY Pathogenesis any process that involves the pituitary and interferes with ACTH secretion can result in secondary adrenal insufficiency panhypopituitarism login to view 1 more bullet isolated ACTH deficiency login to view 1 more bullet medications login to view 2 more bullets Presentation Symptoms fatigue weakness weight loss muscle/joint pain psychiatric symptoms nausea/vomiting diarrhea Physical exam lack of hyperpigmentation (seen in primary adrenal insufficiency) hypotension auricular-cartilage calcification imaging Computed tomography (CT) of the brain indications login to view 2 more bullets Magnetic resonance imaging (MRI) of the brain more sensitive test Studies Serum labs cortisol levels (e.g., morning serum cortisol) login to view 2 more bullets plasma ACTH concentration login to view 2 more bullets ACTH stimulation test login to view 1 more bullet CRH stimulation test login to view 2 more bullets Diagnostic Laboratory Values for Secondary Adrenal Insufficiency Test Result Cortisol Low (5 ug/dL) ACTH Low (<5 pg/mL) ACTH stimulation test Normal CRH stimulation test Normal Differential Primary adrenal insufficiency distinguishing factor login to view 2 more bullets Tertiary adrenal insufficiency distinguishing factor login to view 1 more bullet DIAGNOSIS Diagnosis is often based on clinical presentation and confirmed via laboratory testing Imaging studies used to determine the cause of secondary adrenal insufficiency Treatment Treatment overview management is focused on treating the underlying cause (if any) and providing glucocorticoid replacement login to view 1 more bullet Pharmacologic glucocorticoid replacement therapy login to view 2 more bullets Complications Adrenal crisis medical emergency managed with scheduled IV glucocorticoid