The Full form of RFT is Renal Function Tests. RFTs analyze blood samples to detect any kidney-related problems. Renal function tests are a set of tests performed in blood to assess the kidney damage or kidney failure. Analysis of blood and urine samples can be essential for the evaluation of renal (kidney) function. The parameters on which RFTs are done are Creatinine, Glomerular filtration rate and Urea nitrogen. Creatinine test is used to measure the levels of creatinine in your blood. Creatinine is a waste product from the breakdown of creatine found in your muscle. This test is performed to see how well your kidneys are working. Glomerular filtration rate (GFR) test is also used to check the functioning of kidneys. Glomerular filtration rate is the speed at which blood is filtered per minute. Urea nitrogen test measures the amount of urea nitrogen in the blood. Urea is a waste product formed in the liver as a result of protein breakdown. This urea is then released into the blood by the liver. Normally, it is then removed from the blood by the kidneys. Kidneys filter urea and it gets removed from the body through urination.