Top 5 Kidney Function Tests to Ask for and How to Interpret Them

Research shows that chronic kidney disease (CKD) affects an estimated 37 million people in the United States alone. That’s 15% of the adult population or more than one in seven adults.

While that’s a significant proportion, consider this: Approximately 90% of people with CKD aren’t even aware that they have it. 

Are you one of the approximately 80 million people in the country who is at risk for CKD? If you have diabetes or high blood pressure linked to obesity, the answer is already “yes.”

Kidney function tests can help you better understand the condition of these vital organs. They can also provide clues into your overall health and the steps you can take to lower your risk of disease.

Today, we’re sharing five of these kinds of tests to ask for, along with how to interpret them. Ready to learn more? Let’s dive in!

The Five Kidney Function Tests You Need

We offer a broad range of lab tests that you can order directly online without the need of a doctor. There are seven methods that you can use to select your lab tests that include searching by the body function or the condition you want to research.

To that end, we have multiple tests that offer you an in-depth look at your kidney function so you can better gauge your risk factors for chronic kidney disease (CKD). Let’s take a look at five of these tests below.

1. Renal Function Panel

Our renal function panel is a single test that includes 13 biomarkers.

It’s used to evaluate the level of kidney dysfunction in patients with known risk factors of CKD. A few of the most common risk factors include:

  • Hypertension
  • Obesity
  • Diabetes
  • Family history of kidney disease

To understand more about what this test measures, let’s check out the 13 biomarkers it includes.

Glucose

In a blood glucose test, a technician will take a sample of your blood to measure the amount of a simple sugar called glucose within it. 

The most abundant monosaccharide, glucose is a major source of energy for most of the cells in your body, including those in the brain. Certain hormones, including insulin and glucagon, help control your blood glucose levels.

Urea Nitrogen (BUN) 

The acronym BUN stands for blood urea nitrogen. When protein breaks down within your body, it forms urea nitrogen. A BUN test will measure the amount of urea nitrogen present in your bloodstream.

Creatinine

Creatinine is a waste product. It results from the normal wear and tear that the muscles in your body receive on a regular basis. Before it can eliminate into your urine, creatinine has to filter through your kidneys first.

As implied, a creatinine blood test will measure the level of creatinine in your blood. Through this test, you can gauge how well your kidneys work.

eGFR Non-Afr. American

Another way you can test how well your kidneys are working is to measure your glomerular filtration rate (GFR). To understand the results, it helps to know what glomeruli are.

These are the tiny filters in your kidney that help filter waste from your blood. This particular test measures how much blood passes through these glomeruli every minute. 

eGFR African American

Why are there two separate tests measuring eGFR?

In most cases, African Americans will have a higher GFR than Caucasians and most other races. This is because African Americans have a higher average muscle mass.

Hence, these two separate tests center on slightly different calculations.

BUN/Creatinine Ratio

There’s a biomarker for BUN and one for creatinine. Why is it important to compare the ratio between the two?

The answer becomes apparent when these levels are heightened.

Comparing the ratio between a person’s BUN and blood creatinine can help determine why these concentrations are higher than normal. This imbalance can stem from a variety of factors, including:

  • Conditions that decrease blood flow to your kidneys (e.g. congestive heart failure, dehydration)
  • Increased protein in your diet
  • Gastrointestinal bleeding

In normal cases, the ratio of BUN to creatinine is between 10:1 and 20:1. While the above factors can increase it, the ratio can also diminish due to liver disease and malnutrition.

Sodium

Your body needs sodium to work properly. A type of electrolyte, it’s vital to many important, normal processes, including nerve and muscle function.

Once your body takes in all the sodium it needs, your kidneys help to eliminate any excess through your urine. If your sodium blood levels are too high or low, it might signal that you have an issue with your kidneys or dehydration.

Potassium

Like sodium, your body also needs sodium to work properly. This substance helps your nerves and muscles communicate with each other. It also helps transport essential nutrients into your cells and moves unnecessary waste products into your urine.

A potassium test can reveal abnormal levels of potassium in your blood, which could point to several medical conditions, including kidney disease, high blood pressure, and heart disease.

Chloride

Chloride is another type of electrolyte present in your body. It interacts with others (such as potassium, sodium, and carbon dioxide) to keep your body’s fluids steady, along with its acid/base balance.

A chloride test will dictate the amount of chloride present in your blood’s serum, or its fluid portion. It can help diagnose or monitor conditions, including kidney disease, liver disease, heart failure, and high blood pressure.

Carbon Dioxide

You already know that carbon dioxide is another name for CO2. This test will measure the amount of CO2 in your blood’s serum.

When it comes to your internal systems, most of the CO2 preset exists in the form of a substance called bicarbonate or HCO3.

As such, this test measures your levels of bicarbonate. Your kidneys help to regulate these levels, so understanding them can help you gauge how well they’re functioning. 

Calcium

Calcium is the most prevalent mineral in your body, and it’s also one of the most important ones. As much as 99% of the calcium you intake goes to strengthen your bones and teeth.

The remainder travels throughout your body, where it interacts with your blood, muscle, and cellular fluid. In addition to helping your muscles and blood vessels expand and contract, calcium also secretes hormones and enzymes and sends messages through your nervous system.

Your kidneys work with your parathyroid glands to maintain healthy calcium levels. Thus, this test can help you monitor their performance. 

Phosphate

A phosphate test can help determine how much phosphorus in your blood. Kidney disease, liver disease, and certain bone diseases can cause abnormal phosphorus levels.

Normal, working kidneys are able to remove excess phosphate from your blood. When you have CKD, they’re unable to perform that function. 

Albumin

Albumin is one of the proteins that your liver makes. A serum albumin test will measure the amount of this protein in the liquid portion of your blood.

A condition known as albuminuria means that you have too much albumin in your urine. This can be a sign of kidney disease.

2. Urinalysis, Complete

A dipstick Urinalysis, Complete test can help you assess the chemical constituents present within your urine, as these are directly connected to various disease states.

This microscopic examination can help technicians detect the presence of certain cells and other formed elements.

Some of the things a dipstick examination can monitor include:

  • Acidity (pH)
  • Protein
  • Glucose
  • White blood cells
  • Blood
  • Bilirubin

3. Urine Protein, Total, Random without Creatinine

Proteinuria is the presence of protein in your urine.

This is a symptom that stems from renal disease. Protein concentrations may be increased with diabetes, hypertension, nephritic syndrome, and drug nephrotoxicity. A Urine Protein, Total, Random without Creatinine test can help measure your concentration level.

4. Creatinine Clearance

Creatinine Clearance is another test that can help evaluate your GFR and identify issues with your kidney health.

In this case, “clearance” is the volume of which a measured amount of creatinine can be completely eliminated into your urine over a set period of time.

Under normal conditions, your daily creatinine production will remain fairly constant. The only exception is when you have a massive injury to a muscle.

Your kidneys filter creatinine from your blood into your urine, reabsorbing almost none of it. Thus, if your clearance levels are off-balance, it could signify an underlying issue.

5. Microalbumin, Random Urine with Creatinine

Before overt proteinuria develops, albumin excretion will increase in diabetic patients who are at risk of developing diabetic nephropathy. A Microalbumin, Random Urine with Creatinine test can help patients identify small, abnormal increases in the excretion of urinary albumin (microalbuminuria).

The National Kidney Foundation recommends that all type 1 diabetic patients older than 12 years and all type 2 diabetic patients younger than 70 years have their urine tested for microalbuminuria once a year when they are under stable glucose control.

Lab Tests for Individuals with CKD (Or are High Risk)

In addition to the aforementioned lab tests that can help you screen for CKD indicators, the following 11 kidney lab tests are designed to support individuals that currently have CKD or are at a high risk of developing it.

1. Beta-2-Microglobulin

Beta-2 Microglobulin test measures the amount of a protein called beta-2 microglobulin (B2M) in your blood or urine.

Though it’s commonly used as a tumor marker test for cancer patients, it can also help identify kidney damage in people with kidney disease.

2. PTH, Intact

Standing for parathyroid hormone (PTH), a PTH, Intact blood test measures the level of PTH in your blood. A common way to check for hyperparathyroidism, it’s also used to find the cause of abnormal calcium levels or to check the status of chronic kidney disease.

3. Uric Acid

Uric Acid test is designed to measure the level of uric acid in your blood or urine.

Uric acid is a natural waste product made when your body breaks down chemicals called purines. Purines are found in your body cells and also in some foods such as liver, sardines, dried beans, and beer.

Most uric acid dissolves in your blood, then goes straight to the kidneys, which help it leave through your urine. If your body makes too much uric acid or you’re unable to release any into your urine, it can form crystals in your joints, leading to a condition called gout.

In addition, elevated uric acid levels can also cause lead to kidney stones and kidney failure.

4. Vitamin D

If your kidneys are healthy, they’re rich in vitamin D receptors and able to turn vitamin D into its active form. The opposite also holds true. 

It’s common for people with kidney failure to have lower levels of vitamin D. A Vitamin D test can help determine where your levels fall.

5. CBC

Standing for Complete Blood Count, A CBC test measures the number and quantity of the following in your blood:

  • White blood cells
  • Red blood cells
  • Platelets

Low levels of red blood cells could indicate anemia, which is a very common condition in people with kidney cancer. 

6. Cystatin C with eGFR

Cystatin C is a protein that the cells in your body produce. If your kidneys are in good condition, they’re able to balance the level of cystatin C in your blood. If your levels are too high, it can indicate that your kidneys are not working well.

Often, a Cystatin C with eGFR test is performed in conjunction with an eGFR test. This is because a Cystatin C-based estimate for GFR is often less influenced by your muscle mass or your diet than other, creatinine-based estimates.

7. ANA Screen IFA with Reflex to Titer and Pattern

ANA Screen stands for antinuclear antibodies. High levels of ANAs are associated with rheumatic diseases, including:

  • Systemic Lupus Erythematous (SLE)
  • Mixed connective tissue disease
  • Sjogren’s syndrome
  • Scleroderma
  • Polymyositis
  • CREST syndrome
  • Neurologic SLE

Many of these conditions, including SLE, affect multiple parts of your body, including your blood vessels, joints, kidneys, and brain. An ANA Screen IFA with Reflex to Titer and Pattern test can measure your levels of ANAs.

8. Complement Component C3c

These proteins are part of your complementsystem. This is a critical part of your immune system that helps to kill disease-causing bacteria and viruses.

Complement Component C3c test can measure your C3 protein levels. If your C3 levels are low, this may be a sign that you have lupus. In addition, low C3 levels may also be a sign of the following conditions:

  • A C3 deficiency, characterized by recurrent bacterial infections
  • Various forms of kidney disease

9. Complement Component C4c

Along with C3 proteins, C4c is also a part of your complement system. A Complement Component C4c test can identify the levels of these proteins in your blood.

While low levels can also be a sign of lupus, deficiencies in complement C4 levels are also linked to different forms of kidney disease and chronic hepatitis. 

10. Myoglobin, Serum 

Myoglobin is a protein commonly found in your heart and skeletal muscle tissues. People who have kidney disease should consider a Myoglobin, Serum test, as kidney disease can often result in high levels of myoglobin in the bloodstream.

It’s also useful when doctors suspect someone might have experienced a heart attack. This is because the only time your blood will contain myoglobin is after you’ve experienced an injury to a muscle, your heart muscle being a particularly dominant one.

11. Erythropoietin

Erythropoietin (EPO) is a hormone that’s naturally present in your blood. It’s responsible for telling the stem cells in your bone marrow to create more red blood cells.

Your kidneys are primarily responsible for producing EPO. Measuring these hormone levels with an Erythropoietin test can help you understand if they’re doing their job.

Protect Your Kidney Health with Online Lab Tests

Chronic kidney disease doesn’t discriminate. Nor does it wait.

When you need access to the answers you need, the kidney function tests provide the data that can help you understand the health of your kidney.

If you need help understanding the health of your kidney, we’d love to help. We offer these key kidney lab tests as part of our selection of 2,000 lab tests, and we provide explanations on each biomarker.

You can select your lab tests, order directly online, choose a convenient patient service center near you, and review your test results typically in 1 to 2 days after your blood is collected.

Take charge of your health and get tested today at  UltaLabTests.com/Shop.