Cortisol is a steroid hormone released from the adrenal gland in response to Adrenocorticotropic hormone (ACTH), a hormone produced and secreted by the anterior pituitary gland in the brain. The normal range of cortisol in the blood is 6 - 23 mcg/dL. Higher than normal levels can be associated with an adrenal tumor, Cushing’s disease or ectopic ACTH-producing tumors. Lower than normal levels can be associated with Addison’s disease or hypopituitarism. The function of cortisol is to stimulate gluconeogenesis and activate anti-stress and anti-inflammatory pathways.