Davis's Lab & Diagnostic Tests

Urea Nitrogen, Blood

Urea Nitrogen, Blood is a topic covered in the Davis's Lab & Diagnostic Tests.

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Common Use:
To assist in assessing for kidney function toward diagnosing disorders such as kidney disease and dehydration. Also used in monitoring the effectiveness of therapeutic interventions such as hemodialysis.

Serum collected in a gold-, red-, or red/gray-top tube. Plasma collected in a green-top (heparin) tube is also acceptable.

Normal Findings:
(Method: Spectrophotometry)

AgeConventional UnitsSI Units (Conventional Units × 0.357)
Newborn–3 yr5–17 mg/dL1.8–6.1 mmol/L
4–13 yr7–17 mg/dL2.5–6.1 mmol/L
14 yr–adult8–21 mg/dL2.9–7.5 mmol/L
Adult older than 90 yr10–31 mg/dL3.6–11.1 mmol/L

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