Your kidneys filter waste from your blood. Kidney tests show how well that filter works (eGFR) and whether protein is leaking into your urine (albumin).

One slightly off result is common, for example after not drinking enough. Long-term kidney disease is diagnosed only when results stay outside the range for at least 3 months.

Every lab sets its own normal range, based on its equipment and the people it tests. Always compare your result with the range printed on your own report.

Why this test is done

Routine check, especially with diabetes or high blood pressure
Before or while taking medicines cleared by the kidneys
Swelling, changes in urine, or a family history of kidney disease

What each result means

Creatinine

A waste product from muscle, cleared by the kidneys.

Typical adult range: About 0.74 to 1.35 mg/dL in men and 0.59 to 1.04 mg/dL in women (about 65 to 120 and 52 to 92 umol/L).

If high: Can mean the kidneys are filtering less. It can also rise with dehydration, a lot of muscle, a meat-heavy meal or some medicines.

If low: Usually not a concern; often seen with low muscle mass.

eGFR(estimated glomerular filtration rate)

An estimate of how much blood your kidneys filter each minute, worked out from creatinine, age and sex.

Typical adult range: 90 or more is normal. 60 to 89 is mildly reduced and can be normal with age. Below 60 for 3 months or more suggests chronic kidney disease. Below 15 is kidney failure.

If low: The lower the number, the less filtering. Doctors look at the trend and at urine albumin together.

BUN(blood urea nitrogen, urea)

Another waste product cleared by the kidneys.

Typical adult range: About 6 to 24 mg/dL (urea about 2.1 to 8.5 mmol/L).

If high: Can rise with dehydration, a high-protein diet, bleeding in the gut or reduced kidney function.

Urine albumin-creatinine ratio(ACR, microalbumin)

How much protein (albumin) leaks into your urine.

Typical adult range: Under 30 mg/g (3 mg/mmol) is normal.

If high: Repeated high results can be an early sign of kidney damage, often from diabetes or high blood pressure.

Before the test

Usually no fasting. Avoid hard exercise and a large meat meal in the hours before if you can.
Bring a list of your medicines, including pain killers such as ibuprofen.

Questions to ask your doctor

What is my eGFR, and how has it changed over time?
Do I need a urine albumin test as well?
Should any of my medicines be adjusted for my kidneys?
How often should I be tested?

When to get help fast: Get urgent care if you pass very little or no urine, or have sudden swelling with shortness of breath or confusion. In an emergency, call your local emergency number.

Sources

This guide is general information written in plain words. It is not medical advice and has not been reviewed by a doctor for your situation. Read our medical disclaimer.

Kidney function tests: creatinine, eGFR and BUN explained