A creatinine blood test measures the level of creatinine in your blood, which is a waste product produced by muscles from the breakdown of creatine, a compound used for energy production. Healthy kidneys filter creatinine out of the blood and excrete it in urine. Therefore, the creatinine level in the blood reflects how well the kidneys are functioning in filtering waste
. If the kidneys are not working properly, creatinine builds up in the blood, leading to higher than normal levels. Elevated creatinine levels can indicate kidney disease or impaired kidney function. Conversely, low creatinine levels may be seen with low muscle mass
. The creatinine test is commonly done as part of routine blood work or to monitor kidney health, especially in people with risk factors such as diabetes, high blood pressure, or a family history of kidney disease. It can also be used to track the progression of existing kidney disease or to monitor the effects of medications on kidney function
. In summary, creatinine in a blood test is a key marker used to assess kidney function by measuring the amount of muscle waste product filtered by the kidneys
