Blood Urea Nitrogen (BUN)
- Sample Type
- Standard
- Fasting
- No
- Unit
- mg/dL
BUN measures the amount of nitrogen in the blood that comes from the waste product urea. In a Basic Kidney Profile, it is used alongside creatinine to assess renal excretory function. BUN is particularly sensitive to protein intake and hydration status, making the BUN/Creatinine ratio a key indicator for differentiating pre-renal (dehydration) from intrinsic renal failure.
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Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
BUN can be elevated by non-renal factors such as high-protein diets, gastrointestinal bleeding (digestion of blood proteins), and corticosteroid use. A second opinion helps ensure that an elevated BUN is not misinterpreted as kidney failure when it may actually be a sign of dehydration or GI issues.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Blood Urea Nitrogen (BUN):
Official Sources
- Blood urea nitrogen (BUN) test - Mayo ClinicMayo Clinic
- Blood Urea Nitrogen (BUN) Test - Testing.comTesting.com
Research & Guidelines
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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