Cortisol, Serum (Free Cortisol)

Why This Test Might Be Ordered

Your healthcare provider may recommend this test to evaluate conditions affecting cortisol levels, such as Cushing’s syndrome (overproduction of cortisol), adrenal insufficiency (underproduction), or to monitor treatment for conditions like Addison’s disease or other hormonal imbalances. It may also be used in diagnosing or managing stress-related disorders or to check for pituitary gland issues that influence cortisol production.

What to Expect Before the Test

No special preparation is typically needed, but you may be asked to avoid certain medications or supplements that could affect cortisol levels, such as some steroids or herbal products. If you’re taking medications, discuss them with your provider beforehand. You may also be instructed to fast for a certain period, though this is less common for cortisol tests.

During the Test Process

A healthcare professional will draw blood from a vein in your arm. The process is quick and usually causes minimal discomfort. The blood sample is then sent to a lab for analysis to measure free cortisol levels.

What the Results Mean

Results help determine if your cortisol levels are too high or too low. Abnormal results may indicate underlying health conditions that require further evaluation, such as hormonal imbalances or stress-related issues. Your provider will interpret the results in the context of your overall health and medical history.