Skip to main content

Creatinine

A waste product from muscle metabolism removed by the kidneys. Blood creatinine helps estimate filtration, but muscle mass and other factors affect the result.

CREA
Kidney Function
Measured in umol/L

What it measures

Creatinine is a waste product from muscle metabolism that the kidneys remove from blood. Its concentration is used to estimate kidney filtration as eGFR.

Muscle mass, recent meat intake, creatine supplements and some medicines can affect creatinine independently of filtration. A change in creatinine needs clinical context rather than an assumption that it is either harmless or caused by kidney disease.

Cystatin C can provide complementary information when creatinine is difficult to interpret. An equation using both markers generally estimates filtration more accurately than either alone, although each marker has limitations. A clinician can consider trends, urine tests and other findings alongside the estimate.

What your results mean

Low

Below Range

A low creatinine level can reflect naturally smaller muscle mass or a lighter build. It can also occur in pregnancy, when blood volume increases and creatinine is diluted. If your other kidney markers are within range, this finding does not typically require further action.

Normal

Within Range

Your creatinine level is within the healthy range, which is consistent with normal kidney filtration. Alongside eGFR, this is one of the key markers used to assess kidney health.

High

Above Range

Raised creatinine can reflect reduced kidney filtration or factors affecting creatinine production and removal. Muscle mass, supplements, medicines and recent activity matter. A clinician can review the result alongside eGFR, urine tests and, where useful, cystatin C.

Tests that include Creatinine

See where your Creatinine sits

A blood test that includes Creatinine.

View blood testsExplore all biomarkers