Creatinine
Disclaimer: Information on this page is for educational purposes. Consult a physician to interpret your test results. Health Vault helps track biomarker trends but does not replace medical advice.
What This Test Measures
Creatinine is a muscle metabolism product excreted by the kidneys. More stable than urea and a key marker of glomerular filtration.
Used to calculate eGFR — the primary measure of kidney function.
Muscle mass affects baseline levels: athletes may have higher creatinine without pathology.
Normal Ranges
| Group | Reference Range |
|---|---|
| Men | 0.7–1.3 mg/dL (62–115 µmol/L) |
| Women | 0.6–1.1 mg/dL |
| Children | 0.3–0.7 mg/dL (age-dependent) |
Reference ranges may vary by laboratory and assay method.
Causes of High Levels
- Chronic kidney disease
- Obstructive uropathy
- Rhabdomyolysis
- High meat intake
- Certain drugs (trimethoprim)
Causes of Low Levels
- Sarcopenia and low muscle mass
- Pregnancy (physiologic decrease)
- Amputations
Test Preparation
- Fasting not required
- Avoid heavy exercise for 24 hours
- Report creatine supplements
Related Biomarkers
| Biomarker | Relationship |
|---|---|
| Urea | BUN/creatinine ratio |
| Uric Acid | Purine load |
| Potassium | Electrolytes in CKD |
FAQ
How often should I take this test?
Annually; with CKD — every 1–3 months.
What should I do if my result is abnormal?
Rising creatinine requires eGFR calculation and cause evaluation — do not delay nephrology visit.
Last updated: June 2026