Creatinine
Creatinine is a waste product of muscle that the kidneys continuously clear from the blood. Because it is produced fairly steadily, its level reflects how well the kidneys filter — but it also depends on muscle mass.
| Rating | Range | What it means |
|---|---|---|
| Good | below 100 µmol/L | Within the reference range. |
| Worth improving | 100 – 120 µmol/L | |
| Talk to a doctor | 120 µmol/L and above |
This marker also has 2 age- or sex-specific range sets in the app — the table shows the general one.
Why it matters
It indirectly reflects kidney function; KDIGO recommends assessment via eGFR (creatinine + possibly cystatin C), not just the raw value.
If it’s low
Low creatinine is mostly insignificant; it accompanies low muscle mass, a low-protein diet or pregnancy.
If it’s high
High creatinine often means poorer clearance of the blood (a lower eGFR). But it can simply be the result of large muscle mass, dehydration or a meat meal.
What to do
Interpret it via eGFR (which accounts for age/sex). For the kidneys: enough fluids, control of blood pressure and blood sugar, caution with NSAIDs. Do not measure right after a meat meal or intense exercise.
Read together with
eGFR · Urea · Cystatin C · Microalbumin (urine)
Part of the guide: Kidneys & electrolytes →
Articles about this marker
- Albumin blood test: what low or high albumin meansMarker explained
- Biological age: what it is and how to slow it downSupplements & longevity
- Blood chemistry tests: normal values for ALT, AST, GGT, CRP, CK, creatinine and glucoseReading your report
- Blood test reference values — table by test for adultsReading your report
- High BUN or urea: what it means, with creatinine and the BUN/creatinine ratioMarker explained
- High homocysteine: what it means and how to lower itMarker explained
This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.
Your number, not the average
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