A KFT uses a blood sample to check markers related to kidney function. Your prescription might list a full kidney panel or individual measurements such as urea and creatinine. If the test has been ordered for follow-up, take your previous reports to the clinician who requested it. They can check whether changes in the results are relevant to your care.

Creatinine is one of the blood markers used to estimate how well the kidneys are filtering. Your clinician may read that estimate alongside other blood values, previous reports or a urine test. A single result gives information about one point in time, while repeat testing can show whether a change has persisted. Ask your doctor whether there are specific instructions for the sample or any other tests you should complete at the same visit. Keep the complete report, including the units and reference ranges listed by the laboratory.