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Cortisol level How the Test is Performed:
Adult or child:
Blood is drawn from a vein ( venipuncture ), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood). A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding .
Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to Prepare:
The health care provider may advise you to discontinue drugs that can affect the test (see also "Special considerations"). Drugs that can increase cortisol measurements include estrogen and spironolactone. Drugs that can decrease cortisol measurements include androgens and phenytoin.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How it Feels:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing .
Risks:
- excessive bleeding
- fainting or feeling lightheaded
- hematoma (blood accumulating under the skin)
- infection (a slight risk any time the skin is broken)
- multiple punctures to locate veins
Why this Test is Performed:
Cortisol levels are often measured to evaluate the pituitary function and/or adrenal function.
Normal Values:
8 A.M.: 6 to 23 mcg/dl
Note: mcg/dl = micrograms per deciliter
Abnormal Results:
Greater than normal levels may indicate: Lower than normal levels may indicate: Additional conditions under which the test may be performed:
Cost:
The estimated cost is $50.
Special Considerations:
Physical and emotional stress can increase serum cortisol, because a normal response to stress involves increased secretion of ACTH by the pituitary gland.
Cortisol (or other glucocorticoids) in pharmacological doses (when given as a medication) reduces inflammation and inhibits the immune response . Even at physiological (normal body) concentrations, cortisol probably has an effect on the immune system and the inflammatory response , especially in people subject to chronic stress.
Cortisol is a steroid hormone released from the adrenal cortex in response to ACTH. Normally, cortisol levels rise and fall during the day (that is, diurnal variation); highest levels are at about 6 to 8 A.M. and lowest levels are at about midnight.
Cortisol levels may increase after meals. Cortisol helps to increase the release of amino acids from skeletal muscle , and fatty acids from adipose tissue. The amino acids are taken up by the liver and converted to glucose, which is subsequently secreted into the blood to be used for energy by certain tissues such as brain cells and red blood cells. The fatty acids released from the adipose tissue are used for energy by skeletal muscle, thus sparing the available glucose for use by the brain.
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