Adult: <50 ng/24; SI units: <138 nmol/day
Child: <38 ng/24 hr; SI units: <104 nmol/day
. 24-hr urine collection.
■ Used to screen for adrenal hyperfunction.
■ Result from urinary free cortisol test is a better indication of
cortisol secretion than a single plasma level.
■ Best test for diagnosing Cushing’s syndrome.
