A triple kidney test is a blood draw, not a urine test. Blood draw is the most clear way to assess kidney function, including urea nitrogen, creatinine and glomerular filtration rate. These three tests can make an initial assessment of kidney function. It is advisable to have an empty stomach before the blood draw for the most reliable results of the test. You should tell your doctor what medical history you have and whether you take any medications during the triple kidney function test. Do not drink too much water the day before the test; regular water is fine. For abnormal kidney function there may be certain symptoms, such as low urine or yellow urine volume and proteinuria. Only by making the test can we determine whether the kidney function is normal or not.