Cortisol measures the amount of the hormone, cortisol, in the blood. Cortisol can also be measured using a urine test.

Cortisol Overview

Reviewed: May 13, 2015

Cortisol is important as it affects many different body functions. Cortisol is a hormone released from the adrenal gland.

Cortisol affects metabolism, stress response, immune system function, and nervous system function. Not only can measuring cortisol levels evaluate your body's functions but it can be used to detect diseases such as Addison's Disease and Cushing Syndrome. 

Cortisol levels are measured in (mcg/dL). Normal values for a blood sample taken at 8 in the morning are 6 to 23 micrograms per deciliter (mcg/dL).



Blood draw


Cortisol test must be drawn early in the morning as cortisol levels varies at different times throughout the day. 

You may asked not to exercise vigorously the day before the test.

Tell your doctor about all of the medications you take as they may affect your test. 

What the results mean

A higher than normal cortisol level may indicate:

  • Burns
  • Cushing disease
  • Cushing syndrome
  • Tumor of the adrenal gland that is producing too much cortisol
  • Exercise
  • Hyperthyroidism
  • Shock
  • Stress
  • Surgery

A lower than normal cortisol level may indicate:

  • Addison disease, in which the adrenal glands do not produce enough cortisol
  • Hypopituitarism, in which the pituitary gland does not signal the adrenal gland to produce enough cortisol
  • Suppression of normal pituitary or adrenal function by glucocorticoid medications 
  • Hypothyroidism
  • Low blood sugar