The 24-Hour Urinary Cortisol test measures the amount of cortisol excreted in the urine over a 24-hour period. Cortisol is a hormone produced by the adrenal glands in response to stress and plays a role in various bodily functions, including metabolism and immune response. This test is often used to evaluate the function of the adrenal glands and diagnose conditions such as Cushing’s syndrome (excess cortisol) or Addison’s disease (insufficient cortisol). The test helps provide a more accurate assessment of cortisol levels over a full day, as cortisol levels can fluctuate throughout the day.