Your kidneys perform a variety of essential tasks, such as removing waste from your blood, balancing the water and minerals, and helping your body produce red blood cells. Some people need kidney function tests to ensure their organs are working properly. Here’s how to tell if you need one of these tests and what to expect from them. 

When Do You Need a Test?

Your doctor may recommend a kidney function test if you have a family history of kidney failure or a condition that puts the kidneys at risk, like high blood pressure or diabetes. You may also need a test if you find urinating difficult or painful, if you see blood in your urine, if you need to urinate more often than usual, or if you have swollen feet and hands.

These symptoms may indicate a problem with your kidneys, especially if you’re experiencing more than one of them. A kidney function test can help your doctor identify issues, like chronic kidney disease, kidney stones, and bladder infection.

What Are the Types of Kidney Function Tests?

1. Urinalysis

For this test, you’ll need to either provide a few tablespoons of urine or all the urine you produce in 24 hours. These samples allow your doctor to check for abnormal substances like bacteria, blood, pus, sugar, and protein.

Protein in the urine isn’t always problematic, but excessive amounts can signal an infection. If you provide the 24-hour sample, your doctor can also determine how quickly your kidneys filter out creatinine (a waste product from muscle use).

2. Serum Creatinine Test

For this test, your doctor will draw blood from your arm to check the level of creatinine. If it’s higher than 1.4 milligrams/deciliter (mg/dL) for men or 1.2 mg/dL for women, there may be a kidney issue. 

3. Estimated GFR

Along with a blood sample, this test requires information such as your age, gender, race, height, and weight. The sample and information will help your doctor determine your glomerular filtration rate (GFR), which shows how effectively your kidneys filter waste and excess fluids from your blood. If your GFR is below 60, you may have a kidney problem. 

4. Blood Urea Nitrogen (BUN)

For this test, your doctor will use a blood sample to measure how much urea nitrogen (a waste product from protein) is in your blood. A BUN level that’s higher than 20 mg/dL may indicate a kidney problem. 

Think you might need a kidney function test? Turn to the team at Mt Auburn Nephrology. Located in Cincinnati, OH, these experienced doctors diagnose and treat a variety of issues, including chronic kidney disease, kidney stones, hypertension, and acute renal failure. Learn more about the practice online, and call (513) 841-0222 to schedule an appointment.