Cortisol Test - Diagnose Disorders In Adrenal Or Pituitary Glands

Submitted on March 27, 2012

Cortisol Test

The cortisol test is used to diagnose disorders with the adrenal glands or pituitary glands. This test is asked for when an individual shows symptoms of Cushing's syndrome or Addison's disease.

Cortisol is produced by the adrenal glands, and it helps the body to convert blood glucose and fat to energy by a process called metabolism. It also helps the body to manage stress. The cortisol hormone is required for the body's regular functioning; however, higher or lower cortisol levels can lead to problems.

Since cortisol helps with metabolism, its values are directly related to the body's metabolic activity. Cortisol values are higher during mornings and tend to reduce towards the evening. This is because the body's metabolism is the highest just after waking up in the morning and reduces just before going to sleep in the night.


An elastic band is tightened around the upper arm and blood is collected from the vein for the cortisol test. After the blood is collected, a cotton swab dipped in antiseptic alcohol is provided to clean the area that was pricked. The patient will be asked to take at least 30 minutes of rest and avoid any physical activity before the test. This is because metabolism increases with physical exercise and can cause the cortisol values to rise. Cortisol values are measured in micrograms per deciliter or mcg/Dl. The values are different in adults, children, and newborns.

Normal Cortisol Values

Normal cortisol values are as follows:

  • Adults: 5 to 23 mcg/Dl during mornings and 3 to 13 mcg/Dl in the afternoon
  • Children: 3 to 21 mcg/Dl during mornings and 3 to 10 mcg/Dl in the afternoon
  • Newborns: 1 to 24 mcg/Dl

High Cortisol Values

High cortisol values can be due to the following reasons:

  • Cushing's syndrome, which is caused when the adrenal glands are overactive.
  • A tumor in the adrenal or pituitary glands.
  • Kidney or liver disease
  • Depression
  • Hyperthyroidism
  • Obesity

Pregnancy, usage of birth control pills, and recent surgery can also cause the cortisol values to be higher than normal.

Low Cortisol Values

Cortisol values can be low when the adrenal glands are not working normally. Lower than normal cortisol values can be an indication of Addison's disease or internal bleeding. Typical symptoms of Addison's disease include weakness, fatigue, and high levels of pigmentation.

Severe bleeding during childbirth can damage the pituitary gland of the mother, which, in turn, may reduce the amount of cortisol in the blood.