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Printed on 4/19/2026
For informational purposes only. This is not medical advice.
FEUrea estimates the fraction of filtered urea excreted in urine. It is often used in acute kidney injury when patients are receiving diuretics, because FEUrea is generally less affected by natriuretic therapy than FENa.
Formula: FEUrea (%) = (Urine Urea x Serum Cr) / (Serum Urea x Urine Cr) x 100.
Lower FEUrea values are more consistent with pre-renal kidney hypoperfusion, while higher values suggest intrinsic renal tubular dysfunction in the proper clinical setting.
Use FEUrea during AKI evaluation when the patient is on loop or thiazide diuretics and FENa may be misleading.
Thresholds are not absolute and performance varies by population and timing. FEUrea should be interpreted with full clinical context rather than used as a standalone diagnostic test.
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
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