Test Code 1006
Test Details
Blood Urea Nitrogen (BUN)
Urea is the major end product of protein nitrogen metabolism. Urea is synthesized in the liver and excreted mostly by the kidneys.
Methodology
Enzymatic
Patient Preparation
None
Preferred Specimen
1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST/Tiger Top)
Alternate Specimen
1.0 mL EDTA plasma (0.5 mL minimum) collected in plasma separator tube (Pearl Top)
Transport Temperature
Refrigerated (ship on frozen cold packs)
Stability
Refrigerated: 7 days
Lab Values
Blood Urea Nitrogen (BUN)
- Low: <3.0 mg/dL
- Normal: 3.0-25.0 mg/dL
- High: >25.0 mg/dL
- Alert: >50.0 mg/dL
Clinical Significance
Blood Urea Nitrogen (BUN)
Elevated levels of BUN usually indicate renal damage, or mechanical obstruction of urine excretion.
Treatment Options
Blood Urea Nitrogen (BUN)
- Treatment is based on cause of elevation.
- Consider additional diagnostic tests as indicated.
