What is a creatinine test?This test measures creatinine levels in 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.Other names: blood creatinine, serum creatinine, urine creatinine
