Secondary Adrenocortical Insufficiency

This topic covers secondary adrenocortical insufficiency, which results from inadequate stimulation of the adrenal cortex due to deficiency of ACTH from the pituitary or CRH from the hypothalamus. Zambian tertiary students will learn the most common cause is prolonged administration of exogenous glucocorticoids, which suppresses the hypothalamic-pituitary-adrenal (HPA) axis. Other causes include pituitary tumors, infarction, or trauma. Unlike primary Addison's disease, secondary insufficiency lacks hyperpigmentation (because ACTH is low) and often presents with less severe electrolyte disturbances (aldosterone secretion, which is regulated by angiotensin, is largely preserved). Understanding this distinction is critical for diagnosing the cause of adrenal insufficiency and for managing patients on chronic steroid therapy. This knowledge is essential for endocrinology and internal medicine examinations and for safe clinical practice in Zambia.