Test Overview
Chemiluminescent Immunoassay (CLIA)
Establish diagnosis of adrenocortical insufficiency, Addison's disease, adrenocortical hypersecretion, or Cushing's disease. Malfunction of any of the organs in the hypothalamus - pituitary - adrenal cortex axis will result in alteration of cortisol levels.
AM: 5.3 - 22.5 mcg/dL
PM: 3.4 - 16.8 mcg/dL
Patients undergoing Dexamethasone Suppression (CORTD): <1.8 ug/dL
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Specimen may be stored at room temperature up to 8 hours.
Test Details
4 hours
- Hydrocortisone
- Dexamethasone Suppression Test
Specimen Requirements
Collect specimen in an SST tube or red top. Centrifuge, aliquot serum into a plastic vial and refrigerate at 2-8C up to 48 hours or freeze for longer storage at -20C. Freeze only once. Circulating cortisol levels follow a diurnal pattern. Cortisol values are the highest in the morning and lowest in the evening. A single analysis of serum cortisol is of little diagnostic value because of daily variation. Blood should be drawn in the morning and late afternoon to evaluate baseline diurnal variation. Indicate time and date of draw on requisition.
Red Top Tube
0.5 mL serum
0.25 mL serum