Creatinine
Serum Creatinine
Creatinine is a waste product made by your muscles. Your kidneys remove it from your blood. A blood test measures the amount left, and that result helps calculate eGFR, an estimate of kidney filtering.
Try your Creatinine result.
A quick one-marker check. Vita can score it better once it sees the full lab report around it.
What does a high creatinine result mean?
A rise can mean your kidneys are clearing less creatinine, but muscle mass, food, supplements and medicines can also affect it. A sudden increase from your usual result can matter even if the lab has not flagged it.
Your usual level and eGFR matter more than a universal target
There is no one optimal creatinine value for everyone. Compare the result with your previous readings, eGFR and urine tests. Low creatinine can reflect less muscle mass; it does not automatically mean better kidney function.
Sources: National Kidney Foundation
What can change this result?
What can raise it
- A hard workout, greater muscle mass or a recent cooked-meat meal.
- Creatine supplements or medicines that affect the reading.
- Dehydration or a change in kidney filtering.
What can make it lower
- Having less muscle or losing muscle over time.
- Eating less meat.
- Pregnancy can lower creatinine.
Tell your clinician about recent exercise, meals and supplements. Lowering creatinine by eating less or losing muscle does not mean your kidneys are healthier.
What should I do next?
- Review your eGFR and previous creatinine results with your clinician.
- Mention recent illness, exercise, supplements and medication changes. Do not stop prescriptions on your own.
- Ask whether a repeat sample, urine albumin test or cystatin C test would help clarify the result.
How this test works
Creatinine production varies with muscle mass. eGFR combines creatinine with other information to estimate filtering more usefully than creatinine alone, but that estimate also has limits.