24/07/2026
Kidney function is best assessed using the glomerular filtration rate (GFR), which measures how well your kidneys filter waste from your blood. Because measuring GFR directly is complex, healthcare professionals use eGFR (estimated GFR), a calculation based on a simple blood test that measures creatinine, together with factors such as age and s*x, to estimate how well your kidneys are working. Early changes in eGFR can help detect kidney disease before symptoms appear.