CPT Code:


Test Type: 1.0 mL Serum Kit Based
Stability Time:


Refrigerated: 4 days

Reference Range:


  • Low: <6 µg/dL
  • Optimal: 6-19 µg/dL
  • High: >19 µg/dL


  • Low: <2 µg/dL
  • Optimal: 2-12 µg/dL
  • High: >12 µg/dL


Cortisol is a steroid hormone, in the glucocorticoid class of hormones. It is produced and secreted by the adrenal glands. Cortisol can be measured in blood, saliva, and urine and can be affected by many conditions, such as physical or emotional stress, strenuous activity, infection, or injury. It is involved in regulating blood sugar, blood pressure, and inflammation.


Electrochemiluminescence Immunoassay (ECLIA)


  • Cortisol testing is used to help diagnose problems of the pituitary gland or adrenal glands, such as making too much or too little hormones. Testing is used to diagnose Cushing syndrome, a condition associated with excess cortisol, or conditions associated with deficient cortisol such as adrenal insufficiency or Addison disease, tuberculosis, infection of the adrenal glands, or congenital adrenal hyperplasia (CAH). Cortisol levels can also be affected by thyroid abnormalities.
  • Elevated cortisol levels can have adverse effects on the immune system, memory, and sugar metabolism. If a patient has a high blood cortisol, HCPs may consider a cortisol challenge (i.e. adrenocorticotropic hormone (ACTH) to dx Addison’s disease.
  • Many medications such as corticosteroid influence blood cortisol levels.
  • High doses of biotin (> 5 mg/day) may interfere with assay results. Patient assumed to be refraining from biotin supplementation for at least 3 days prior to blood draw.

Collection Details:

Collection Instructions:

Preferred Specimen

1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST / Tiger Top)

Transport Temperature

Refrigerated (ship on frozen cold packs)


Refrigerated: 4 days