An Introduction to the Kidneys and Chronic Kidney Disease
VI. Diagnosing Chronic Kidney Disease and Kidney Failure
A. Tests Used to Help Diagnose Chronic Kidney Disease
If you have an increased chance of developing kidney disease because of other health problems or because you have a family history of kidney disease, or if a kidney problem is suspected, your doctor will probably ask you to have a number of tests that provide clues about kidney function. These will give your doctor a clearer picture of how much kidney function has been lost and help the doctor develop both short - and long-term treatment plans. These tests will also help your doctor determine whether you need to start a treatment for kidney failure, such as dialysis or a kidney transplant. Among the tests you may be asked to take are:
- urinalysis to check for the presence of protein, glucose, ketones, red and white blood cells, bilirubin, bacteria, crystals and casts in your urine. This test is important for detecting early kidney disease and should be part of routine physical examinations for everyone. Protein in the urine may also be an early warning sign for possible development of heart disease.
- blood tests to measure the level of wastes, such as urea and creatinine in your blood and to estimate your remaining kidney function
- tests to measure your level of kidney function, such as glomerular filtration rate, or GFR. Your GFR is usually estimated from the results of your blood creatinine test and your weight, body size, age, and sex. It is considered the best for measuring kidney function and is particularly important for monitoring kidney function in people who have an increased chance of developing kidney disease and in those who already have kidney disease.
- ultrasound or ct scan to check for abnormalities in kidney size and placement, biopsy, kidney stones and estimate residual urine.
- kidney biopsy (removal of small pieces of kidney tissue for examination under the microscope) helps to:
- identify a specific disease process and determine whether it may respond to treatment
- evaluate how much damage has occurred in the kidney
- find out why a kidney transplant may not be doing well.
Your blood pressure should be checked regularly.
B. Stages of Chronic Kidney Disease
The diagnostic tests, especially GFR, will help the doctor determine the stage of your chronic kidney disease. Knowing the stage of your disease helps the doctor plan the best treatment for you. The stages of chronic kidney disease are as follows:
- Stage I: Some kidney damage has occurred, but GFR is still in the normal range of more than 90.
- Stage II: There is kidney damage with mild decrease in GFR (60 to 89)
- Stage III: A moderate decrease has occurred in GFR (30 to 59)
- Stage IV: A severe decrease has occurred in GFR (15 to 29). Your doctor will speak to you about the different treatment options for kidney failure. This would also be a good time to attend a National kidney Foundation "People Like Us, Live" workshop to learn more about the different treatment options. Contact your local National Kidney Foundation office or call the national toll-free number 1-800-622-9010 for more information.
- Stage V: When GFR falls below 15, your kidneys are not working well enough to maintain your overall health, and you will need to start dialysis or receive a kidney transplant. With your doctor's help, you and your family should have already decided on the best treatment for you and taken the steps needed to prepare you to start that treatment.
