Urea
Disclaimer: Information on this page is for educational purposes. Consult a physician to interpret your test results. Lissa Health helps track biomarker trends but does not replace medical advice.
What This Test Measures
Urea is the end product of protein metabolism, excreted by the kidneys. Elevation reflects reduced glomerular filtration or increased protein catabolism.
Sensitive to hydration: dehydration raises urea. Evaluated with creatinine (BUN/creatinine ratio).
Used for screening and monitoring chronic kidney disease.
Normal Ranges
| Group | Reference Range |
|---|---|
| Men | 7–24 mg/dL BUN (2.5–8.3 mmol/L) |
| Women | 7–24 mg/dL |
| Children | 5–18 mg/dL |
Reference ranges may vary by laboratory and assay method.
Causes of High Levels
- Chronic kidney disease
- Dehydration
- High-protein diet
- GI bleeding
- Corticosteroids
Causes of Low Levels
- Hepatic failure
- Low-protein diet
- Pregnancy
- Overhydration
Test Preparation
- Fasting preferred
- Maintain normal fluid intake
- Report diuretics
Related Biomarkers
| Biomarker | Relationship |
|---|---|
| Creatinine | Kidney function |
| Uric Acid | Purine metabolism |
| Albumin | Nephrotic syndrome |
FAQ
How often should I take this test?
Annually; with CKD — every 1–3 months.
What should I do if my result is abnormal?
Elevation with edema and reduced urine output — urgent nephrology evaluation.
Last updated: June 2026