What is a creatinine test?

This test measures creatinine levels in the blood and/or urine. Creatinine is a waste product made by your muscles as part of regular, everyday activity. Normally, your kidneys filter creatinine from your blood and send it out of the body in your urine. If there is a problem with your kidneys, creatinine can build up in the blood, and less will be released in urine. If blood and/or urine creatinine levels are not normal, it can be a sign of kidney disease.

What is it used for?

A creatinine test is used to see if your kidneys are working normally. It's often ordered along with another kidney test called blood urea nitrogen (BUN) or as part of a comprehensive metabolic panel (CMP). A CMP is a group of tests that provide information about different organs and systems in the body. A CMP is frequently included in a routine checkup.

Why do I need a creatinine test?

You may need this test if you have symptoms of kidney disease. These include:

• Fatigue
• Puffiness around the eyes
• Swelling in your feet and/or ankles
• Decreased appetite
• Frequent and painful urination
• Urine that is foamy or bloody

You may also need this test if you have certain risk factors for kidney disease. You may be at higher risk for kidney disease if you have:

• Type 1 or type 2 diabetes
• High blood pressure
• A family history of kidney disease