| Subject | Contents |
| Definition | A blood test that measures the amount of cortisol (a steroid hormone produced from the adrenal cortex). |
| Alternative Names | Hydrocortisone test |
| 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 for the test | 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 synthetic glucocorticoids, like prednisone and prednisolone. 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:
infant test or procedure preparation (birth to 1 year) toddler test or procedure preparation (1 to 3 years) preschooler test or procedure preparation (3 to 6 years) schoolage test or procedure preparation (6 to 12 years) adolescent test or procedure preparation (12 to 18 years) |
| How the test will feel | 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. |
| Why the 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 |
| What abnormal results mean | Greater than normal levels may indicate: adrenal tumorCushing's syndrome ectopic ACTH-producing tumors Lower than normal levels may indicate:Addison's diseasehypopituitarism Additional conditions under which the test may be performed: acute adrenal crisisectopic Cushing's syndromepituitary Cushing's (Cushing's disease) |
| What the risks are | excessive bleedingfainting or feeling lightheaded hematoma (blood accumulating under the skin) infection (a slight risk any time the skin is broken) multiple punctures to locate veins |
| Special considerations | Cortisol is a steroid hormone released from the adrenal cortex in response to ACTH. Normally, cortisol levels rise and fall during the day repeating on a 24 hour cycle (diurnal variation); highest levels are at about 6 to 8 A.M. and lowest levels are at about midnight. Physical and emotional stress can increase serum cortisol, because a normal response to stress involves increased secretion of ACTH by the pituitary gland. |
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