Has your doctor explained how the severity of your chronic kidney disease (CKD) is monitored and determined? Your healthcare team completes a number of tests that indicate the extent of your kidney damage, your remaining kidney function, and your risk of disease progression. Here, the National Kidney Fund explains how these tests are done, what they measure, and what their results mean for you.*

What tests determine kidney health status? 

There are a number of tests your doctor may run to monitor your overall health in general, and your kidney health specifically. The two main tests are:

• Estimated glomerular filtration rate (eGFR). A calculation that estimates your kidney function from your blood creatinine level, age, body size, and gender. It ultimately tells how well your kidneys filter and clean your blood of toxins and wastes. 
• Urine albumin-creatinine ratio (uACR). A urine test will check for blood or albumin (a type of protein) in the urine, which is oftentimes an early sign of CKD. 

Based on the results of those tests, your doctor may order further tests, including: 

• Imaging tests, like an ultrasound or CT scan, to provide pictures of your kidneys and urinary tract for your healthcare team’s review. These images offer more details, such as whether or not a kidney stone or tumor is present, as well as the overall structure of the kidney and urinary tract, to make sure they’re sound.
• A kidney biopsy, in which a small slice of your kidney is removed and examined under a microscope, to help identify specific types of kidney disease, and inform diagnosis and treatment

How do I match my stage of CKD to my eGFR level?

CKD is divided into multiple stages based on your eGFR rate and shows the severity of kidney function loss. Your eGFR number represents the percentage of kidney function that you have remaining. The rates of eGFR associated with each stage are: 

• Stage 1 (normal function): 90-100 eGFR
• Stage 2 (mild loss): 60-89 eGFR
• Stage 3a (mild to moderate loss): 45-59 eGFR
• Stage 3b (moderate to severe loss): 33 to 40 eGFR
• Stage 4 (severe loss): 15-29
• Stage 5 (kidney failure): Less than 15

As we age, it is natural for eGFR to decrease. This is why using uACR and eGFR together is important for determining the risk of your CKD progressing. The higher your uACR (amount of protein in your urine), the greater the risk of your CKD getting worse. The CKD Heat Map is used by your doctor to determine your risk and develop the best treatment plan for you.   

What can you do to protect kidney function?

Fortunately, there are many things you can do to decrease protein in your urine and protect your kidney function. These include:

• Get your kidney numbers (eGFR and uACR) checked at least once a year 
• Treat high blood pressure if you have it
• Manage blood sugars well if you have diabetes
• Avoid or limit the use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen
• Avoid smoking
• Follow a healthy lifestyle that includes regular exercise and a heart-healthy diet
• Maintain or achieve a healthy weight for your particular frame 
• Consult your doctor before taking any vitamins, minerals, herbs, or other supplements, as some can worsen CKD
• Have a pharmacist review your medications to ensure you take the right dose for your age and kidney function 

CKD can advance slowly and silently. Check-in regularly with your doctor and healthcare team to discuss your health status, numbers, and treatment plan. 

*Kidney Failure Risk Factor: Estimated Glomerular Filtration Rate. (2022, September 23). National Kidney Foundation. https://www.kidney.org/content/kidney-failure-risk-factor-estimated-glomerular-filtration-rate-egfr