24-Hour Urinary Free Cortisol

Why This Test Is Done

Your doctor may order a 24-hour urinary free cortisol test to check for conditions like Cushing’s syndrome, which occurs when your body makes too much cortisol. It can also help diagnose adrenal gland disorders, pituitary issues, or other hormonal imbalances that affect cortisol production.

How the Test Works

You’ll collect all your urine for a full 24-hour period in a special container. The collected urine is then sent to a lab for analysis to measure the total cortisol excreted during that time.

Sample Collection Process

You’ll start by emptying your bladder completely into the toilet. Then, you’ll use the provided container to collect all urine for the next 24 hours, including during sleep. Remember to change the container daily. Finally, you’ll empty your bladder again into the container at the end of the 24 hours. Keep the collected urine refrigerated until you return it to the lab.

What to Expect Before the Test

No special preparation is needed, but avoid taking any medications that might affect cortisol levels (like some steroids) unless your doctor advises otherwise. Drink plenty of water to help flush cortisol naturally.