How to check your kidney function
Quick answer: To check your kidney function, enter your creatinine, add your age and sex, read your eGFR stage and add urine ACR if you have it.
- Enter your creatinine. In mg/dL or µmol/L, as on your report.
- Add your age and sex. They're needed to calculate eGFR, the best single measure of kidney filtering.
- Read your eGFR stage. 90 or more is normal, 60–89 mildly decreased (common with age), and below 60 for three months or more is chronic kidney disease.
- Add urine ACR if you have it. Protein in the urine is an early sign of kidney stress, especially with diabetes or high blood pressure.
What eGFR means
eGFR estimates how many millilitres of blood your kidneys filter each minute. It's calculated here with the CKD-EPI 2021 equation, which doesn't use race. A single low value can be caused by dehydration, illness or a high-meat meal, so doctors look for a lasting change.
Protecting your kidneys
Keeping blood pressure and blood sugar under control, not smoking, staying hydrated and avoiding regular use of painkillers like ibuprofen all help. Diet advice for kidney disease depends on the stage: get it from your kidney team.
Important
This tool explains results in plain words; it can't diagnose anything. Your doctor reads them alongside your symptoms, history and medicines.
Frequently asked questions
Is an eGFR of 70 bad?
It's in the mildly decreased range (G2), which is common with age and isn't kidney disease on its own unless there are other signs such as protein in the urine.
Why is my creatinine high?
Reduced kidney filtering is one cause, but so are dehydration, high muscle mass, creatine supplements, a big meat meal before the test and some medicines.
What if a result is flagged as far outside the range?
Some results, such as very high potassium or very low hemoglobin, can need prompt care. If the checker shows a red warning, contact a doctor or urgent care the same day, and call emergency services if you feel very unwell.
Are my results uploaded or stored?
No. The report is read inside your browser, on your device. Nothing is sent to a server or saved after you close the page.