Diagnosis of Chronic Kidney Disease
by Diane W. Shannon, MD, MPH
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You will also have a few tests, including:
Commonly Ordered Blood Tests
Urine Protein Level
During the filtering process, the kidneys usually return protein to the circulation. With chronic kidney disease, the kidneys allow protein to leak into the urine. Different kinds of proteins can leak into the urine. Albumin is a protein that often appears in the urine of people who have chronic kidney disease caused by high blood pressure or diabetes.
Different tests can be used to check for protein in the urine.
Blood Urea Nitrogen (BUN) and Creatinine Levels
Creatinine and BUN are waste products that the kidneys usually remove from the blood. When the kidneys are damaged, the creatinine and BUN levels rise in the blood. A simple blood test can measure these levels.
Estimated Glomerular Filtration Rate
The glomerular filtration rate (GFR) is a measurement of how well the kidneys are processing wastes. Your doctor can calculate the GFR based on your:
The formula used in clinical practice is called the Cockcroft-Gault equation:
Creatinine clearance or GFR (mL per minute) = (140 – age) X body weight in kilogram ÷ 72 X serum creatinine. If calculating for a female, this product is multiplied by 0.85.
The GFR determines the stage of chronic renal disease.
Urinary Tract Ultrasound or CT Scan
Your doctor may order an ultrasound or a CT scan to evaluate your kidneys, ureters, and bladder. These tests can tell your doctor if you have a kidney stone, tumor, or other structural problem that may have caused the chronic kidney disease.
Your doctor may recommend a kidney biopsy, unless you have small kidneys or have end-stage renal disease. During a kidney biopsy, a small piece of kidney tissue is removed and examined under a microscope. The biopsy can tell how much kidney damage has already occurred. It also may determine the cause of your kidney disease.
Your doctor may order the following tests to determine the underlying disease causing your chronic kidney disease:
Are you at increased risk for chronic kidney disease? National Kidney Foundation website. Available at: http://www.kidney.org/atoz/pdf/atriskckd.pdf . Published 2010. Accessed October 16, 2012.
Chronic kidney disease. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed . Updated October 12, 2012. Accessed October 16, 2012.
Johnson CA, Levey AS, Coresh J, Levin A, Lau J, Eknoyan G. Clinical practice guidelines for chronic kidney disease in adults: Part II. glomerular filtration rate, proteinuria, and other markers. Am Fam Phys. 2004; 70:1091-1097.
Snively CS, Gutierrez C. Chronic kidney disease: prevention and treatment of common complications. Am Fam Phys. 2004;70:1921-1930.
Last reviewed October 2012 by Adrienne Carmack, MD
Last Updated: 10/31/2012