Urinary free cortisol is a measurement of the cortisol in urine that is not attached to other proteins (free). Free cortisol represents the active form of the hormone. The urine measurement directly refelcts the blood level of cortisol. This test helps diagnose Cushing’s syndrome, and Addison’s disease. INCREASED levels of urine cortisol may indicate Cushing syndrome, or a tumor that releases ACTH. While DECREASED levels may indicate Addison’s disease, hypopituitarism, or congenital adrenal hyperplasia. See Cortisol, Total, Serum
State 24 Hrs urine volume. Boric acid is an acceptable preservative. Avoid samples preserved with HCl or acetic acid. If samples are collected without preservative they should be frozen immediately.