1. What is BUN/Creatinine Ratio?

The BUN/Creatinine ratio is a diagnostic measurement that compares the levels of blood urea nitrogen (BUN) to creatinine in the blood. It helps differentiate between various causes of acute kidney injury and provides insight into hydration status and kidney function.

2. How Does the Calculator Work?

The calculator uses the simple ratio formula:

Where:

• BUN — Blood Urea Nitrogen in mg/dL
• Creatinine — Serum creatinine in mg/dL

Explanation: The ratio compares nitrogen waste products in the blood (BUN) to muscle waste (creatinine), both of which are normally filtered by the kidneys.

3. Clinical Significance

Details: Normal ratio is typically 10:1 to 20:1. Higher ratios may suggest prerenal causes (dehydration, heart failure), while lower ratios may suggest intrinsic renal disease or liver disease.

4. Using the Calculator

Tips: Enter BUN and creatinine values in mg/dL. Both values must be greater than zero. The result is a unitless ratio.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal BUN/Creatinine ratio?
A: Typically 10:1 to 20:1, though this varies slightly by laboratory and population.

Q2: What does a high ratio (>20:1) indicate?
A: May suggest prerenal azotemia (dehydration, heart failure, gastrointestinal bleeding) or high protein intake.

Q3: What does a low ratio (<10:1) suggest?
A: May indicate intrinsic renal disease, liver disease, low protein intake, or rhabdomyolysis.

Q4: Are there limitations to this ratio?
A: Yes, it should always be interpreted in clinical context with other lab values and patient history.

Q5: Does this ratio change with age?
A: The ratio tends to increase slightly with age due to reduced muscle mass affecting creatinine levels.