24/03/2026
Three Key Tests for Kidney Disease
Diagnosing kidney disease typically involves a combination of tests that assess how well these vital organs are functioning. Early detection is crucial, as kidney disease often presents with few symptoms in its initial stages. The primary diagnostic tools include blood tests, urine tests, and in some cases, imaging tests or a kidney biopsy.
Blood Tests
Blood tests are fundamental in evaluating kidney function. The most common blood test measures the estimated glomerular filtration rate (eGFR). This calculation uses the level of creatinine in the blood, along with factors like age, s*x, and size, to determine how many milliliters of waste the kidneys can filter per minute. A healthy eGFR is typically above 90 ml/min. A lower eGFR can indicate kidney damage.
Another important blood test is the blood urea nitrogen (BUN) test, which measures the amount of urea nitrogen in the blood. Urea nitrogen is a waste product from protein breakdown that healthy kidneys remove from the blood. Elevated BUN levels can suggest impaired kidney function. Additionally, some doctors may use a cystatin C test to calculate eGFR, particularly when creatinine-based results might be less accurate, such as in individuals who are very muscular or elderly.
Urine Tests
Urine tests play a critical role in detecting signs of kidney disease that blood tests might miss. A key urine test is the albumin-to-creatinine ratio (uACR), which measures the amount of albumin (a type of protein) in the urine compared to creatinine. Healthy kidneys prevent albumin from passing into the urine, so its presence can be an early indicator of kidney damage, especially in individuals with conditions like diabetes or high blood pressure.
Routine urine tests can also reveal other clues about kidney health, such as the presence of blood or protein. A dipstick test is a quick method to check for albumin in urine. If albumin is found, further testing may be recommended to confirm the results.
Imaging Tests and Biopsy
Beyond blood and urine analysis, imaging tests can provide a visual assessment of the kidneys. An ultrasound is commonly used to view the structure and size of the kidneys,