Urea Nitrogen (BUN) : 294

Test Code

BUNAU or 294

Alias/See Also

Blood Urea Nitrogen, BUN

CPT Codes
84520

Transport Container

Preferred Specimen
1 mL serum

Alternative Specimens
Sodium heparin (green-top) tube or Lithium heparin (green-top) tube

Minimum Volume
0.5 mL

Transport Temperature

Room temperature.

Specimen Stability

Room temperature: 7 days; Refrigerated: 5 days; Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Anticoagulants other than heparin

Methodology
Spectrophotometry

Setup Schedule

Sunday - Saturday

Report Available

1 day

Reference Range

Male (mg/dL) Female (mg/dL)

<1 Month 4-12 3-17

1-11 Months 2-13 4-14

1-3 Years 3-12 3-14

4-19 Years 7-20 7-20

≥20 Years 7-25 7-25

Clinical Significance

Urea is the principle waste product of protein catabolism. BUN is most commonly measured in the diagnosis and treatment of certain renal and metabolic diseases. Increased BUN concentration may result from increased production of urea due to (1) diet or excessive destruction of cellular proteins as occurs in massive infection and fevers, (2) reduced renal perfusion resulting from dehydration or heart failure, (3) nearly all types of kidney disease, and (4) mechanical obstruction to urine excretion such as is caused by stones, tumors, infection, or stricture. Decreased urea levels are less frequent and occur primarily in advanced liver disease and in overhydration.

Performing Laboratory
med fusion

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.