Cortisol, 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 insufficiency (too little cortisol), or other hormonal imbalances. It can also be used to monitor stress responses or evaluate pituitary gland function.

What to Expect Before the Test

You’ll collect all urine produced in a 24-hour period (typically from one morning to the next morning). Drink plenty of fluids to ensure full collection. Avoid certain medications that might affect cortisol levels (like some steroids) unless instructed otherwise.

How the Test Works

After collecting urine samples, the lab processes them to measure cortisol concentration. The results are compared to a reference range to determine if levels are within normal limits or if further evaluation is needed.

What the Results Mean

Elevated levels may indicate overproduction of cortisol (e.g., from tumors, excess steroid use, or Cushing’s syndrome). Low levels could suggest adrenal gland problems or insufficient hormone release. Your doctor will interpret results in the context of your symptoms and medical history.