Patient education: Renal function panel (The Basics)

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") – These are waste products in the blood. The kidneys work to filter them out.

●Electrolytes – These are minerals and other substances that the body needs to work properly. They include sodium, potassium, chloride, and bicarbonate.

●Calcium and phosphorus – These are minerals the body needs for the bones, muscles, and heart to be healthy.

●Albumin – This is a type of protein found in blood.

●Blood glucose – This is also known as blood sugar.

The renal function panel can show how much of these substances is in the blood. Having too much or too little of some of these substances can be a sign of a problem.

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

●Estimated glomerular filtration rate ("eGFR") – This tells your doctor how much blood your kidneys can filter in 1 minute.

●Anion gap – This compares the difference between the number of positively charged electrolytes and negatively charged electrolytes in your blood. It can tell your doctor if you have an acid-base disorder.

●BUN-to-creatinine ratio – This compares the amount of BUN and creatinine in your blood.

Why might I get a renal function panel? — Your doctor might order a renal function panel:

●If you have symptoms of a kidney problem

●If you are at risk for developing kidney problems

●To check if you have an electrolyte or fluid imbalance

●As part of a routine check-up

●To check how well your kidneys are working, if you have already been diagnosed with a kidney problem

You might also get a renal function panel if your results on a different type of blood test were abnormal.

Based on the results of your renal function panel, your doctor or nurse will decide if you need other tests or treatment.

How do I prepare for a renal function panel? — For this test, you need to get a "blood draw." Your doctor or nurse will tell you where to go for this.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing the blood to get to your arm.

What happens during a blood draw? — For the blood draw, a needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure that your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your renal function panel shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out what the cause is.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

More on this topic

Patient education: Serum creatinine test (The Basics)
Patient education: Blood urea nitrogen test (The Basics)
Patient education: Electrolyte panel (The Basics)
Patient education: Calcium blood test (The Basics)
Patient education: 24-hour urine collection (The Basics)