Kidney screening explained

Not sure when to get your kidneys checked or what it involves? A Mediclinic expert explains what you need to know. 

One of the reasons people often don't realise their kidneys aren't functioning properly is because early kidney disease usually doesn't show any symptoms, says Dr Adriano Pellizzon, a physician and nephrologist at Mediclinic Panorama.

If you live with conditions like diabetes, hypertension, heart disease, obesity, or have a family history of kidney problems, you’re at higher risk of kidney disease. That’s why it’s important to get your kidneys tested regularly. Patients with diabetes or hypertension should have an annual screening. Your healthcare professional can tell you how often you should get tested, especially if you have other health conditions.

Kidney testing is also recommended if you’re experiencing symptoms like painful or frequent urination, or blood in the urine. “It’s crucial to detect problems early on, as this allows us to begin treatment and prevent the condition from worsening,” Dr Pellizzon explains.

Blood tests

Healthcare professionals can use different blood tests to check how well your kidneys are working. These tests look for different substances in your blood. For instance, tests for urea and creatinine levels measure waste products created from breaking down protein and muscle. When kidney disease is present, these levels often rise.

Why eGFR is important

Glomeruli are tiny filters in your kidneys that help remove toxins (waste) from your blood. Estimated glomerular filtration rate (eGFR) measures how much blood these filters clean every minute based on your body size. The estimated glomerular filtration rate (eGFR) measures the rate these filters clean your blood every minute. The formula combines results from a serum creatinine blood test with information like your age and gender.

An eGFR of above 90 is normal; anything below this indicates you may be developing kidney disease and warrants investigation. A decreasing eGFR shows the kidney failure has progressed, and you may need dialysis or a transplant. “When kidney disease is detected early, we can avoid these types of treatment,” Dr Pellizzon says.

Urine tests for kidney screening

Urine tests are another way to detect both early and advanced kidney disease. They typically check for protein and albumin in the urine. Healthy kidneys usually prevent these substances from leaking into the urine. Your doctor may also perform a urinalysis, which examines other cells in the urine that can give clues about the type of kidney disease present.

A urine dipstick is a quick, easy screening test that your doctor can perform in their office. It involves dipping a plastic stick, marked with small squares of paper, into a urine sample. Each square changes colour if substances like blood or protein are present in the urine. This helps your doctor pinpoint potential issues, allowing for further investigation.

Other urine tests include a spot urine protein analysis (urine protein: creatinine ratio) and a 24-hour urine collection. These tests measure protein levels in urine, with higher protein content often indicating kidney disease. For the 24-hour collection, you'll need to collect all urine over a 24-hour period in a plastic bottle, which is then sent to the lab for analysis. You may need to repeat the test several times to confirm the results.

Once your doctor shares the results of your kidney screening tests, they’ll discuss the next steps, including treatment options. It’s important that you and your doctor keep track of your test results over time, as they reveal whether your condition is stable.

To find a nephrologist near you, go to www.mediclinic.co.za