Creatinine is a waste product produced by the muscles during the normal process of muscle breakdown. A spot creatinine test is a simple blood or urine test that measures the level of creatinine in the blood or urine at a particular point in time. The creatinine spot test is used to check kidney function and to diagnose kidney disease. Creatinine levels in the blood or urine can also be used to calculate the glomerular filtration rate (GFR), which is a measure of how well the kidneys are functioning. The test is easy to perform and results can be obtained quickly, making it a useful tool for routine monitoring of kidney function.
