Serum Creatinine (Creatinine)

What Does This Test Measure?

Creatinine is a byproduct of muscle metabolism that your kidneys filter from your blood. High levels may indicate poor kidney function, while low levels could suggest dehydration or muscle loss. This test is often used alongside other kidney function tests to evaluate kidney health.

Why Might You Need This Test?

Doctors order creatinine tests to monitor kidney function, especially in people with conditions like diabetes, high blood pressure, or a history of kidney disease. It may also be used before surgeries, during pregnancy, or if you have symptoms like swelling, fatigue, or changes in urine output.

How Is This Test Done?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure creatinine levels. No special preparation is needed, but you may be asked to stop certain medications or avoid certain foods for a short time if instructed by your healthcare provider.

What Are Common Results?

Results are typically reported in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). While exact reference ranges can vary by lab, higher-than-normal levels may signal kidney problems, while very low levels might indicate dehydration or muscle wasting. Your doctor will interpret results in the context of your overall health.