Know Your Numbers: Kidney Labs

Chronic Kidney Disease (CKD) is known as a "silent killer" because symptoms may not appear until later stages of the disease (there are 5 stages of kidney disease - read more about them here). Even if you don't have Kidney Disease, it's hereditary. Let your physician know about your family history of CKD so they can monitor your kidney function.

This is why it's important for you to keep up with your annual check-up. Your physician will order relevant labs for further health assessment, and will review labs with you either in-person or over the phone. If you have results out of the normal/reference ranges, your physician will likely order follow-up labs for confirmation and diagnosis.

Be active in your own healthcare

Review your results and ask as many questions as needed for you to feel comfortable with your results.

You may or may not have all of these labs in your results - your physician will determine which labs are necessary. Dietitians assist physicians in providing further explanation of nutrition-related labs and how your diet can impact your health. Here is a breakdown of some kidney-relevant labs.


Estimated Glomerular Filtration Rate (eGFR or GFR)

Chart provided by the National Kidney Foundation (

Chart provided by the National Kidney Foundation (

This is a calculation based on your gender, age, size, and creatinine in your blood. This is one of the best tests to assess your kidney function. A normal GFR is above 90. Some lab reports will look for GFR of at least 60, as function will naturally decline as we age. GFR is associated with stages of kidney disease. Kidney failure is associated with a GFR below 15. Not just one low value will suggest kidney disease. Generally, a low GFR for three months will indicate kidney disease with diagnosis from a physician. Calculate your eGFR here.

Albumin-to-Creatinine Ratio (ACR)

This test is performed with a urine sample. It will assess if you are leaking protein through your urine, a sign of kidney damage. Generally, a result less than 30 mg/g will indicate normal kidney function. If your ACR is between 30-300 mg/g for at least three months, it may indicate kidney damage.



The #1 mineral stored in our body. Calcium helps with many things including bone health and muscle contraction. General calcium levels are between 8.5 - 10.2 mg/dL. As our kidneys help regulate our bone health, calcium becomes an important value to monitor with kidney disease.


A mineral found in our body - the second highest in quantity. Phosphorus does plenty of things to help keep us healthy, such as manage how your body uses energy, build strong bones and teeth, regulate vitamin use, and help with muscle contraction (including our heart!). Phosphorus level should generally be approximately 2.5 - 4.5 mg/dL, but ranges may differ depending on the individual. Working with a dietitian can help assess current diet habits and identify the top phosphorus culprits in your diet.


The third most abundant mineral in our bodies. Potassium acts as an electrolyte and helps with nerve conductivity, muscle contraction, and fluid balance. Potassium level is generally between 3.5 - 5.0 mEq/L. High- and low-potassium values should be reviewed quickly with your physician and healthcare team as potassium plays an important role with our hearts. A dietitian can help by reviewing your diet to balance your potassium level.

Interested in discussing your own lab results and what they mean?

Reading your lab results can be an overwhelming and a scary task to do alone, so that's why I'm here. I will help break down your results and work with you to create a plan that best suits your life and health goals. It's so important to individualize health and nutrition plans! EveryBODY is different.

Ask your doctor for a dietitian referral so we can work together to achieve your goals! Contact me to request a dietitian referral form, print it out, then email or drop it off at your physician's office. The medical staff can complete and send directly to me. Then all you have to do is book your first session with me!

If you are looking to check your kidney health, the National Kidney Foundation may be providing a free screening near you. Screenings may entail blood draws and urine screenings to assess your kidney function. To find the closest screening, look up your nearest location here.



Disclaimer: Information provided by Jen Hernandez RD LLC is not intended to be used for medical diagnosis or treatment. The information is intended for general consumer health and understanding. The information provided is not intended to be a substitute for professional medical advice or treatment. Please consult with your doctor prior to starting or changing your diet or medications.