Cortisol is the major adrenal glucocorticoid steroid hormone, and is normally under feedback control by pituitary ACTH and the hypothalamus.
Causes of low cortisol include pituitary destruction or failure, with resultant loss of ACTH to stimulate the adrenal, and metabolic errors or destruction of the adrenal gland itself (adrenogenital syndromes, tuberculosis, histoplasmosis). The diagnosis of hypoadrenalism generally requires confirmation with ACTH stimulation, due to the circadian rhythms of cortisol and other factors. Causes of increased cortisol, which may present initially simply as loss of normal diurnal variation, include pituitary overproduction of ACTH, production of ACTH by a tumor (notably oat cell cancers), and adrenal adenomas.
A significant deviation from the normal range may require further evaluation by your physician.Includes:
Cortisol, AMPatient Instructions:
Specimen must be collected during the morning hours, before 10:00 AM. This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H or coenzyme R). It is recommended to stop biotin consumption at least 72 hours prior to the collection of specimen. Categories: Hormones and Metabolism