Morning ACTH Hormone Test - Adrenocorticotropic Hormone (ACTH) Test, Morning

This test measures the level of adrenocorticotropic hormone (ACTH) in blood plasma in the morning (usually between 7 and 9 a.m.), which is the time of its peak natural secretion. ACTH is secreted by the anterior pituitary gland in response to corticosteroid-releasing hormone (CRH) from the hypothalamus and stimulates the adrenal cortex to produce cortisol. The test is used to evaluate the hypothalamic-pituitary-adrenal (HPA) axis and diagnose disorders of hypercortisolism or hypocortisolism.