What tests do doctors use to diagnose kidney disease?

At your annual exam, your doctor may suggest tests to show how well your kidneys work. One is a blood test, and the other is a urine test.

Since there are only a few signs in the early stages of kidney disease, these tests are vital. If they show signs of kidney disease, your doctor will let you know how to proceed.

Blood test

A simple blood test shows your estimated glomerular filtration rate (eGFR). To do the test, your doctor takes a sample during a routine blood draw.

Your doctor checks the sample for creatinine. This waste product, produced by the muscles, is usually filtered out by the kidneys. If the kidneys are damaged, there may be excess creatinine in the blood.

Urine tests

Protein builds up in the urine because the kidneys can’t filter them out. Albumin is the most common type of protein found when the kidneys are damaged. A routine urine test can indicate whether there is protein in your urine.