Is my Creatinine normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal Creatinine level?
Creatinine is a waste product from muscle metabolism, filtered out by the kidneys. Rising creatinine indicates declining kidney function. Normal is 0.5-1.1 mg/dL, but varies with muscle mass, age, and sex. It's used to calculate eGFR, the gold standard for kidney function assessment. 37 million Americans have chronic kidney disease.
| Range | Values |
|---|---|
| Standard Reference | 0.5–1.1 mg/dL |
| High Risk | > 1.3 mg/dL |
What causes abnormal Creatinine levels?
High creatinine is caused by chronic kidney disease (most common), acute kidney injury, dehydration, high-protein diet, creatine supplementation, intense exercise, certain medications (NSAIDs, ACE inhibitors), and conditions that reduce blood flow to the kidneys. Low creatinine is less common and may indicate low muscle mass or advanced liver disease.
When should you see a doctor?
See your doctor if creatinine is above 1.2 mg/dL (men) or 1.1 mg/dL (women) on repeat testing, especially if trending upward. Also consult if you have risk factors for kidney disease: diabetes, high blood pressure, family history, or age over 60. Your doctor should calculate eGFR and may order a urine albumin test.
Creatinine and longevity
Kidney function is a cornerstone of longevity — the kidneys filter 180 liters of blood daily, regulate electrolytes, produce erythropoietin, and activate vitamin D. Creatinine is an imperfect kidney marker because it is influenced by muscle mass, diet (high-protein and creatine supplementation elevate it), and hydration status. Cystatin C is emerging as a superior alternative that is independent of muscle mass. Chronic kidney disease (CKD) affects 37 million Americans, 90% of whom are undiagnosed. The two leading causes — diabetes and hypertension — are both modifiable. Longitudinal creatinine trending (watching the trajectory over years) is more informative than any single measurement.
Where to get a Creatinine test
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Related biomarkers
These biomarkers are often tested alongside Creatinine for a more complete picture.
Frequently asked questions
What is a normal creatinine level?
Can creatinine be high without kidney disease?
What is the relationship between creatinine and eGFR?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.