24-Hour Urinary Free Cortisol

Why This Test Matters

Cortisol is a hormone produced by your adrenal glands, which sit on top of your kidneys. It helps your body respond to stress, regulate metabolism, and maintain blood pressure. Measuring cortisol in urine over 24 hours gives a more accurate picture of your body’s natural cortisol production than a single blood test.

What to Expect Before the Test

You’ll collect all your urine for a full 24-hour period, starting and ending with your first urine sample of the next day. Keep track of the time and store urine in a refrigerator until you return it to the lab. Avoid certain medications that might affect cortisol levels, like some steroids or blood pressure drugs, unless your doctor advises otherwise.

How the Test Works

The test measures cortisol’s concentration in your urine, which reflects how much cortisol your body releases naturally. This method helps identify patterns of cortisol release that might indicate health issues.

Possible Results and Next Steps

High levels may suggest conditions like Cushing’s syndrome, where the body produces too much cortisol. Low levels could indicate adrenal insufficiency or problems with the pituitary gland. Your doctor will discuss results with you and may recommend further testing or treatments.