Cortisol, Serum (Mass Concentration)

Why Is This Test Done?

Your healthcare provider may order this test to diagnose or monitor conditions affecting your adrenal glands, such as Cushing’s syndrome (too much cortisol), adrenal insufficiency (too little cortisol), or to check for issues related to stress or hormone imbalances. It may also be used in the evaluation of certain types of tumors or to assess response to treatment for conditions involving cortisol.

What Does the Test Involve?

A blood sample is taken from a vein in your arm. You may feel a slight pinch or discomfort, but it usually doesn’t cause significant pain. The blood is then sent to a lab for analysis.

What to Expect Before the Test

No special preparation is usually needed, but if your provider has instructions (such as fasting or avoiding certain medications), follow them carefully. For example, some tests may require you to avoid certain foods or supplements for 24 hours before the blood draw.

What to Expect After the Test

You can typically resume your normal activities immediately after the blood draw. There may be a small bruise or slight soreness at the site, but this usually fades quickly. If you experience excessive bleeding, swelling, or other unusual symptoms, contact your healthcare provider.