Answer:
Glomerular Filtration Rate (GFR) is a test that measures how well the kidneys are filtering waste from the blood. The test is usually done by collecting a sample of the patient's blood and measuring the amount of a certain waste product (usually creatinine) in it. The GFR can be used to detect and monitor kidney disease. It is also useful in predicting the risk of developing kidney disease in the future. GFR tests can also be used to monitor the effectiveness of treatments for kidney disease.