Your kidneys are made up of thousands of tiny filters called Nephrons. Your kidney function is determined by how well these filters are working. The filters in your kidney work much the same way that a water filter works - they clean your blood by removing the waste products that then leave the body via the urine, and they return the clean blood to keep circulating around your body.
The degree to which your kidneys are working and filtering your blood is measured by your Glomerular Filtration Rate or GFR. You GFR is very difficult to measure in the body, so it is calculated using an equation. The equation uses the amount of Creatinine (a waste product) in your blood, as well as your sex and age to work out an estimated GFR (eGFR).
Your eGFR is roughly equivalent to the degree of kidney function you have, so an eGFR of 60 would mean that your kidneys are only working at about 60%. eGFR is the best measure of how well your kidneys are working and in Australia, these results are reported on blood test results for individuals aged 18 years and over.
Your GP of Nephrologist will monitor your eGFR regularly, as a declining eGFR is a sign that your kidney disease is getting worse.
For more information about eGFR and what your eGFR number mean, please refer to our eGFR fact sheet.