Testing & Self-Assessment
eGFR
Estimated Glomerular Filtration Rate
One of the most widely used lab measures for assessing kidney function.
What it is
eGFR estimates how well the kidneys filter waste from the blood. It is calculated from a blood creatinine (or cystatin C) level along with age, sex, and sometimes race, using standardized equations rather than measured directly.
How it's used
eGFR is used to stage chronic kidney disease and track its progression over time. Because it's an estimate, trends across multiple readings are generally more informative than any single result.
Limitations
eGFR equations can be affected by muscle mass, diet, hydration, and other individual factors, so results should always be interpreted by a qualified healthcare provider alongside other tests such as creatinine and urine albumin.
See the Kidney Function Explorer for how eGFR relates to other kidney-health markers.