About BUN / Creatinine Ratio
The BUN (Blood Urea Nitrogen) / Creatinine Ratio is a calculated blood test marker that assesses kidney function. The ratio helps differentiate between conditions that affect blood flow to the kidneys from those that damage the kidneys themselves. Urea is a waste product formed in the liver, while creatinine is a waste product from muscle metabolism, both of which are filtered by the kidneys.
Reference Values
Optimal Range
10.0 - 20.0 ratio
Women's Optimal Range
10.0 - 20.0 ratio
Elite Value
Not specified
Health Implications
High
Elevated levels may indicate dehydration, congestive heart failure, or gastrointestinal bleeding, necessitating immediate medical evaluation.
Low
Low levels may be associated with liver disease or malnutrition, suggesting the need for further diagnostic testing to ascertain underlying causes.
Symptoms
High
May include fatigue, nausea, vomiting, dehydration, confusion, high blood pressure.
Low
Can include dizziness, muscle weakness, low energy, difficulty concentrating.
Lifestyle Factors
Specimen Type
Testing Methods
Also Known As
Scientific Sources
- 1. Levey, A. S., Eckardt, K. U., Dorman, N. M., Christiansen, S. L., Hoorn, E. J., Ingelfinger, J. R., ... & Cheung, M. (2020). Nomenclature for kidney function and disease: report of a Kidney Disease: Improving Global Outcomes (KDIGO) consensus conference. *Kidney International*, 97(6), 1117-1129.
- 2. Inker, L. A., Eneanya, N. D., Coresh, J., Tighiouart, H., Wang, D., Sang, Y., ... & Levey, A. S. (2021). New creatinine- and cystatin C–based equations to estimate GFR without race. *New England Journal of Medicine*, 385(19), 1737-1749.
- 3. National Kidney Foundation. (2022). Clinical practice guideline for the evaluation and management of chronic kidney disease: 2022 update. *American Journal of Kidney Diseases*, 79(3), A1-A3.
- 4. Kidney Disease: Improving Global Outcomes (KDIGO) Diabetes Work Group. (2020). KDIGO 2020 clinical practice guideline for diabetes management in chronic kidney disease. *Kidney International*, 98(4S), S1-S115.
- 5. Levey, A. S., Stevens, L. A., Schmid, C. H., Zhang, Y. L., Castro, A. F., Feldman, H. I., ... & Coresh, J. (2009). A new equation to estimate glomerular filtration rate. *Annals of Internal Medicine*, 150(9), 604-612.