Renal Lab Tests

How To Read and Understand Your Renal Lab Tests

So it is that time of the year again, you have to go get your bloodwork done and check on your kidney function. Maybe you get your labs checked every three months, or maybe less often. Regardless of the time, you should feel confident in understanding your bloodwork. So this post will walk you through how to read and understand your renal lab tests with CKD.

What Are Renal Lab Tests?

Renal labs are a set of laboratory tests that are used to assess the function of the kidneys. These tests provide valuable information about the health of the kidneys and can help diagnose and monitor kidney disease.

If you’re not familiar with renal labs, reading the results can be intimidating. But with a little bit of understanding, you can easily interpret the results and understand what they mean.

It’s important to note that the specific tests ordered may vary depending on the individual’s medical history and symptoms. It’s also important to interpret the results in the context of the individual’s overall health and medical history. If you have concerns about your kidney function, talk to your healthcare provider about appropriate testing and monitoring.

So, here’s what you need to know.


Creatinine (pronunced say “kree-AT-uh-neen”) is a waste product produced by the muscles and excreted by the kidneys. A high level of creatinine in the blood is a sign of decreased kidney function. Normal creatinine levels are typically under 100 µmol/L.

Some things to consider:

  • Not do any strenuous exercise for 2 days (48 hours) before having the tests.
  • Not eat more than 225 grams (8 oz) of meat, especially beef, or other protein for 24 hours before the blood creatinine test and during the creatinine clearance urine test.
  • Drink plenty of fluids if you are asked to collect your urine for 24 hours. But don’t drink coffee or tea. These are diuretics that cause your body to pass more urine than normal.

Check out this post for more information on creatinine and renal lab tests.

Blood Urea Nitrogen (BUN)

Blood Urea Nitrogen (BUN) is a waste product produced by the liver and excreted by the kidneys. An increased BUN level can indicate dehydration, kidney damage, or other medical conditions. Normal BUN levels typically range from 2.1 to 8.5 mmol/L.

Estimated Glomerular Filtration Rate (eGFR)

EGFR is a measure of how well the kidneys are functioning. It is calculated based on age, sex, race, and serum creatinine level. A GFR of 90 or above is considered normal, while a GFR below 60 is an indicator of kidney disease. eGFR is used to calculate your stage of CKD. For more information on the stages of CKD check out this post. This is important for your renal lab tests.

Electrolytes for Renal Lab Tests

Electrolytes are minerals in the blood that help regulate many bodily functions, including heart rhythm, nerve function, and muscle contractions. These are often the most commonly tested electrolytes you may see in your renal lab tests.

  1. Potassium: A routine test for seeing how much potassium is in your blood. 
  2. Sodium: A sodium blood test is a routine test that may be used to check your general health. It may be used to help find and monitor conditions that affect the balance of fluids, electrolytes, and acidity in your body. It is not necessarily a measure of how much salt you are eating.
  3. Calcium and Phosphorus: These tests are used to assess bone health, which can be affected by kidney disease. High phosphorus levels and low calcium levels can indicate kidney disease.
  4. Parathyroid Hormone (PTH): This test measures the level of PTH in the blood, which is produced by the parathyroid gland to regulate calcium and phosphorus levels in the body. Elevated levels of PTH can indicate kidney disease.
  5. Vitamin D: This test measures the level of vitamin D in the blood, which is important for bone health. People with kidney disease often have low vitamin D levels.

Urine Albumin-to-Creatinine Ratio

UACR measures the amount of protein, specifically albumin, in the urine relative to the amount of creatinine. A high UACR indicates kidney damage and can be an early sign of kidney disease. Normal UACR levels are typically less than 30 mg/g.

Understanding Your Renal Lab Tests

Understanding the results of renal labs can be a bit daunting, but it is essential for detecting kidney dysfunction or other medical conditions. By familiarizing yourself with the above tests and their normal ranges, you can better interpret the results and discuss any abnormalities with your healthcare provider.

Do You Want To Preserve Your Kidney Function?

If you’re looking to make changes to your nutrition or learn about what you should be eating for CKD my Kidney Nutrition Fast Track course is here to help get you started. Learn about it here.

Want to work together? Connect with Kidney Nutrition here.

Want to learn more about Emily? Learn more here.

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