Nephrology Patient Resources

What is a renal function panel? A renal function panel is a blood test that checks how well the kidneys are working. It is also called a "kidney function panel." It measures the levels of certain substances in the body. The word "panel" means that multiple tests are done on the same blood sample.

A renal function panel measures the:

• Creatinine and blood urea nitrogen ("BUN") - Creatinine and blood urea nitrogen are waste products found in your blood that your kidneys help remove. Creatinine comes from the normal breakdown of your muscles, so everyone has some in their blood. A normal creatinine level is usually less than one, but this can change depending on your age, race, and body size. Blood urea nitrogen (BUN) is another waste, and a normal range is between 6 and 20 mg/dL. These normal levels can also vary based on your age, sex, and muscle mass, protein intake, and hydration state. Your kidney care team can help you understand whether your numbers are normal for you.
• Cystatin C - Cystatin C is a small protein made by almost every cell in your body. It is found in your blood, just like creatinine. Your kidneys help remove cystatin C from your blood. A normal level is less than 1. If the level is higher than normal, it may mean your kidneys are not working as well and are cleaning your blood more slowly.
• Electrolytes- These are minerals that help your body work properly. They include sodium, potassium, chloride, and bicarbonate.
  • Sodium: Sodium is a mineral found in many foods and is a main part of salt. Your sodium level helps us understand how much water your body is holding. A low sodium level can happen when your body holds onto too much water, which can occur in advanced kidney disease. A high sodium level can occur when you are not drinking enough water. A normal sodium level is between 133 and 145 mmol/L.   
  • Potassium: Helps the nerves, muscles, and heart work properly. Too much or too little potassium can be dangerous and may cause heart problems. Normal range, 3.3-5.1 mmol/L.
  • Chloride: Helps keep the balance of fluids and acids in your body. Normal range, 96-108 mmol/L.
  • Bicarbonate: Helps keep your body’s acid-base balance steady. Normal range, 21-28 mmol/L.
• Calcium and phosphorus - These minerals help keep your bones muscles, and heart healthy. Calcium normal range, 8.6-10.2 mg/dL. Phosphorus normal range, 2.7-4.5g/dL.
• Albumin - A protein found in blood that helps keep fluid in your bloodstream and helps some medicines work better. Normal range, 3.5-5.2 g/dL.
• Blood glucose - Also called blood sugar. Normal fasting range, 60-99 mg/dL. 

The renal function panel shows how much of these substances are in your blood. Having too much or too little of some of these may be a sign of a problem.

Your doctor uses the test results to understand how well your kidneys are working. The results also help to calculate:

• Estimated glomerular filtration rate ("eGFR") - Shows how much blood your kidneys can filter each minute. Learn more about estimated filtration rate (National Kidney Foundation)
• Anion gap - Measures the difference between certain minerals in your blood to check for acid-base balance problems. Normal range, 7-16.
• BUN-to-creatinine ratio - Compares the amount of BUN and creatinine in your blood. Normal range, 10-20.

Urinalysis - Examines the physical, chemical, and microscopic properties of urine.

Albumin and protein testing - When there is albumin (a type of protein) in your urine, it is called albuminuria or proteinuria. If your kidneys are healthy, you should have little to no protein in your urine. If your kidneys are damaged, protein can “leak” out of the kidneys into your urine. A normal amount of albumin in your urine is less than 30 mg/g. Anything above 30mg/g may mean you have kidney disease.

Protein to creatinine test - This test measures the amount of protein in your urine compared to the amount of creatinine, a waste product, also in urine. This test helps detect early signs of kidney damage, even if no symptoms are present. A normal amount of albumin in the urine is less than 30mg/g per gram of creatinine.

A kidney biopsy (also called a renal biopsy) is a procedure used to diagnose kidney problems.  Learn more about kidney biopsy.

Once the lab finishes testing, your results will be available on the “patient portal,” MyChart.

• If any results are abnormal, you will get a message in MyChart or a phone call with next steps.
• If your results are normal, you will not get a message or call.

Please bring any non-urgent questions about your results to your next nephrology clinic visit.