A simple test can estimate the volume of blood that is filtered by your kidneys over a given period of time.
This test is called the estimated glomerular filtration rate (eGFR). A normal eGFR is 90 ml/min/1.73m or more. The eGFR test involves a blood test and measures a substance called creatinine which comes from the normal breakdown of muscle. If your kidneys are not working properly the level of creatinine in the blood goes up. The eGFR is calculated from your age, sex and blood creatinine level.
|Stage of Chronic Kidney Disease||eGFR ml/min/1.73m|
|Stage 1 - The eGFR is normal. Some people may still have some kidney damage or disease with a normal test. For example, you may have some protein or blood in your urine, an abnormality of your kidney, kidney inflammation, etc.||90 or more|
|Stage 2 - Mildly reduced kidney function AND you are already known to have some kidney damage or disease. People with an eGFR of 60-89 without any kidney damage or disease are not considered to have CKD.||60 to 89|
|Stage 3 - Moderately reduced kidney function.||30 to 59|
|Stage 4 - Severely reduced kidney function.||15 to 29|
|Stage 5 - Very severely reduced kidney function. This is sometimes called end-stage kidney failure or established renal failure.||Less than|
About 1 in 10 people have some degree of CKD. It can develop at any age and various conditions can lead to CKD. It becomes more common with increasing age. About half of people aged 75 or more have some degree of CKD. Most cases of CKD are mild or moderate, produce no symptoms. They do not need any treatment but should be monitored with further tests at least once a year.
If the CKD progresses to stage 3 or more then various other tests will be done. An early morning urine test will be checked for microscopic blood or protein leaking through the kidneys into the urine and blood tests will be checked for anaemia and possibly an altered level of a hormone called parathyroid hormone (PTH). PTH is involved in the control of the blood level of calcium, phosphate and bone metabolism. A raised PTH will be treated with Vitamin D and calcium supplements.
For a more detailed description of CKD and how the kidney read this leaflet on Patient UK.