Order a kidney function test and check your kidneys

Because the kidneys quietly do their work, you often notice little of a changing kidney function at first. A kidney function test can give you concrete data where you would otherwise only be guessing.

This panel measures creatinine, eGFR and urea, so you can map your kidney values and have a baseline to compare against later.

This test may suit men who:

• follow a high-protein diet and want to check their kidney markers
• have kidney-related conditions in the family
• use supplements such as creatine and want to track their kidneys
• simply want a baseline of their kidney health

This kidney function test measures three markers in your blood:

• Creatinine (umol/l): a waste product of your muscle metabolism that your kidneys normally filter out efficiently.
• eGFR (ml/min): the estimated glomerular filtration rate, which indicates how well your kidneys filter blood.
• Urea (BUN) (mmol/l): a byproduct of protein metabolism; elevated levels may suggest your kidneys are clearing waste less readily.

Creatinine and eGFR are connected: an elevated creatinine with a lower eGFR may point to reduced filtration capacity. Urea adds another layer, as it reflects both your kidney function and your protein intake.

By looking at the three markers together you get a more reliable picture than any single value. Deviations can have various causes and do not automatically indicate a problem.

For this test, blood is drawn at a certified sample point. There are 700+ locations across the Netherlands, which you choose yourself after ordering.

It is a blood test without a referral: you pick a location and a time yourself. The draw usually takes only a few minutes.

This test may be useful if you follow a high-protein diet, use creatine supplements, have kidney issues in your family, or simply want a baseline. Many men choose to have their kidneys tested after a period of creatine use or a strict protein diet.

It can also be relevant with symptoms such as a changed urination pattern, unexplained swelling or persistent fatigue.

Your result shows whether each marker falls within the reference range. An elevated creatinine or urea, or a lower-than-expected eGFR, may be a reason to look further.

Factors such as your muscle mass, hydration and diet can influence these kidney values. A doctor can interpret your result within your personal health profile.

You usually do not need to fast for this test. It can help to drink normally on the day of the draw, as strong dehydration can temporarily affect your kidney values. If in doubt about medication or supplements, check with your doctor.

Your results are available online within a few working days. You log in to your account and view each marker with its reference range and a clear explanation. If you want to view your kidneys alongside wider markers, look at the broader complete metabolic panel.

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