Free urine cortisol (24-hour)
The test determines the level of free cortisol — the biologically active fraction of adrenal cortex hormone excreted in urine over 24 hours. Allows assessment of daily cortisol secretion, independent of its intraday fluctuations. Used to diagnose hypercorticism and hypocorticism, including Cushing's syndrome and disease. Applied to detect adrenal function disorders in chronic stress and endocrine diseases.
What the test evaluates:
- Free cortisol concentration in 24-hour urine
- Adrenal cortex functional state
- Intensity of stress hormone secretion throughout the day
Biomaterial: Urine
- Urine collected strictly over 24 hours
- First morning portion not collected; all subsequent urine collected during the day
- Exclude physical activity, emotional stress, alcohol, caffeine 24 hours before and during collection
- Store collected urine in cool place
Medications:
- Glucocorticoids, hormonal drugs, and some psychotropic agents may distort results
- Medication discontinuation only by physician agreement
Recommended for:
- Suspected adrenal diseases and Cushing's syndrome
- Chronic fatigue, weakness, metabolic disorders
- Persistent or resistant arterial hypertension
- Stress-related, psychosomatic, and asthenic conditions
Elevated level: possible hypercorticism, Cushing's syndrome, adrenal or pituitary tumors, severe chronic stress
Reduced level: may indicate adrenal cortex insufficiency (Addison's disease) or adrenal function suppression.
