BUN/Creatinine Ratio
Understand BUN/Creatinine Ratio to evaluate kidney function and hydration status. Monitor renal health with precision tracking.
What is BUN/Creatinine Ratio?
The BUN/creatinine ratio compares blood urea nitrogen to creatinine levels, helping differentiate between kidney dysfunction causes. Since BUN and creatinine are eliminated differently by the kidneys, their ratio provides clues about underlying pathology.
Why is it Tested?
Doctors calculate this ratio to distinguish prerenal (before the kidney), intrinsic renal (within the kidney), and postrenal (after the kidney) causes of elevated creatinine. It helps identify dehydration, heart failure, or urinary obstruction versus primary kidney disease.
Normal Ranges
Reference ranges vary by lab. General adult guidelines:
- Adults: 10–20 (ratio)
The ratio helps interpret kidney function when creatinine is elevated. Values outside this range, combined with clinical context, guide further evaluation and treatment decisions.
Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.
What do Abnormal Results Mean?
Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.
Elevated Ratio (>20)
High ratios suggest prerenal causes:
- Dehydration or volume depletion
- Heart failure
- Gastrointestinal bleeding
- High protein intake
- Certain medications (steroids, tetracyclines)
Low Ratio (<10)
Low ratios may indicate:
- Intrinsic kidney disease
- Low protein diet
- Liver disease
- Pregnancy
- Muscle wasting conditions
How to Track Over Time
The BUN/creatinine ratio fluctuates with hydration status, protein intake, and kidney function changes. Tracking patterns alongside individual BUN and creatinine values provides insight into kidney health trends and helps monitor response to treatments affecting fluid balance.
Track your BUN/Creatinine Ratio results over time
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