Serum Creatinine: Normal Range, High & Low Causes
What Creatinine measures
Creatinine is a waste product from normal muscle use. Healthy kidneys remove it from the blood, so a rising level can mean the kidneys are filtering less well.
Creatinine reference ranges
| Category | Conventional units | SI units |
|---|---|---|
| Adult men | 0.74 – 1.35 mg/dL | 65 – 119 µmol/L |
| Adult women | 0.59 – 1.04 mg/dL | 52 – 92 µmol/L |
Doctors usually turn creatinine into an eGFR, which adjusts for age and sex and is the better measure of kidney function.
Need to convert units? Use the mg/dL ↔ µmol/L converter.
Common causes of a high result
- Reduced kidney function (acute or chronic kidney disease)
- Dehydration
- Heavy meat meal or creatine supplements shortly before the test
- Some medicines, including certain antibiotics and NSAIDs
- Large muscle mass (naturally higher)
Common causes of a low result
- Low muscle mass, older age or frailty
- Pregnancy
- Malnutrition
- Severe liver disease
How to prepare for the test
Usually no fasting. Avoid very heavy exercise and large cooked-meat meals before the test, and drink water normally.
How often to retest
As advised. People with kidney disease or diabetes are often tested at least yearly.
Track Creatinine over time
Upload your reports and Labgist plots every Creatinine result on one timeline, converts units and shows what changed.
Get the appFrequently asked questions
What is a normal creatinine level?
About 0.74–1.35 mg/dL in men and 0.59–1.04 mg/dL in women, with differences between labs.
Can dehydration raise creatinine?
Yes. Mild dehydration can raise creatinine temporarily, which is one reason a single high result is usually repeated.
Why is creatinine reported in two units?
US labs use mg/dL, while many other countries use µmol/L. Multiply mg/dL by 88.4 to get µmol/L.
Related tests
Sources
This page is general education and was last updated 2026-10-30. It is not a substitute for medical advice. See our editorial approach.