How you prepare

A standard blood test is used to measure creatinine levels in your blood (serum creatinine). Your doctor may ask you not to eat (fast) overnight before the test.

For a creatinine urine test, you may need to collect urine over 24 hours in containers provided by the clinic.

For either test, you may need to avoid eating meat for a certain period before the test. If you take a creatine supplement, you'll likely need to stop use.