Kidney function test: check your kidney values

Changes in kidney function often develop gradually and may only cause symptoms once the filtering capacity has declined significantly. A kidney function test can give you preventive insight into how your kidneys are working right now.

By measuring creatinine, urea and eGFR together, you get a practical overview of your kidney values. This is not a diagnosis, but a snapshot you can discuss with a doctor.

A blood test of your kidneys may suit people who:

• want to check their kidney health preventively as part of a general check
• have a family history of kidney conditions
• take medications that can affect kidney function
• have a condition such as high blood pressure or diabetes that may strain the kidneys over time
• had previously abnormal kidney values and want to follow up

This panel measures three kidney-related markers in your blood:

• Creatinine: a waste product of normal muscle metabolism that your kidneys filter from the blood. An elevated value may suggest reduced filtration.
• Urea (BUN): a waste product of protein metabolism, also filtered by your kidneys. The value can vary with diet and hydration.
• eGFR (estimated glomerular filtration rate): calculated from your creatinine and an estimate of how efficiently your kidneys filter.

A standalone creatinine test gives less context than this panel, in which the three values are viewed together. You can read more on the pages about creatinine, urea (BUN) and eGFR.

Elevated creatinine combined with a reduced eGFR may suggest that your kidneys are not filtering as efficiently as expected. Urea adds context, since it is influenced by protein intake and hydration as well as kidney function. Together, these three markers give a clearer picture than any one of them alone.

A single set of results is always a snapshot. Your values can fluctuate with hydration, diet and physical activity. A doctor can help you determine whether your results indicate a trend or a temporary variation.

For this blood test, blood is drawn at a certified sample point. There are 650+ locations across the Netherlands, which you choose yourself after ordering.

You do not need to see your GP first: this is a blood test without a referral, where you pick a location and a time that suit you. The draw is done by trained staff and usually takes only a few minutes.

Testing your kidneys can be useful when:

• you want a focused check on your kidney filtration without a full metabolic panel
• you take medications that can affect kidney function, such as certain pain relievers or blood pressure medication
• you have a condition that may strain your kidney health over time
• you want to establish a baseline for future comparison

Each marker is shown with your value and its reference range. An eGFR above 90 is generally considered normal. Values between 60 and 89 may or may not indicate something, depending on other factors. An eGFR below 60 on repeated testing may suggest reduced kidney function that warrants further evaluation.

With a kidney values blood test, a single number says little on its own. Your report includes an explanation for each marker, and we recommend discussing the result with a doctor, especially if values fall outside the expected range or if you have risk factors.

Your results are usually available online within a few working days. The report includes your values with reference ranges and a clear explanation. If a value falls outside the expected range, this is highlighted.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.