24-Hour Urinary Free Cortisol (Mass Concentration)

Why This Test Is Done

Your doctor may order this test if they suspect conditions like Cushing’s syndrome (too much cortisol), adrenal gland issues, or to check cortisol levels in people with unexplained weight changes, high blood pressure, or unusual fatigue. It’s also used in research or specialized evaluations for hormonal imbalances.

What to Expect Before the Test

No special preparation is needed, but you’ll collect your urine for 24 hours, starting and ending with your first morning urine. Store all samples in a refrigerator until you return them to the lab. Follow your doctor’s instructions carefully to ensure accurate results.

What Happens During the Test

You’ll collect every drop of urine for a full day, including overnight. Use a clean container for each void, and discard the first morning urine at the start of the collection. Return all samples to the lab within 24 hours of completion.

What the Results Mean

Results are compared to standard ranges for healthy adults. High levels may indicate Cushing’s syndrome or other adrenal disorders, while low levels could suggest adrenal insufficiency or other hormonal issues. Your doctor will interpret results in the context of your symptoms and medical history.