Creatinine Test Test
A creatinine test measures the level of creatinine in your blood or urine to check how well your kidneys are working. Creatinine is a waste product from normal muscle activity that your kidneys filter out. If levels are not normal, it may be a sign of kidney disease.
What this test measures
This test measures creatinine levels in a sample of your blood and/or urine. Creatinine is a normal waste product made when you use your muscles and some muscle tissue breaks down.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
High for you may be a sign of kidney disease or injury, including infection, poor blood flow to the kidneys, a blockage in the urinary system, or kidney failure. It may also be caused by dehydration, muscle disorders, intense exercise, a diet high in meat, or certain health problems in pregnancy.
Lower-than-normal results
Low for you may be a sign of malnutrition or a condition that causes muscles to get smaller, such as a long illness, a nerve disorder, or muscle loss from aging. Serious liver disease can also lead to low levels.
Frequently asked questions
What is a creatinine test?
A creatinine test measures the level of creatinine in your blood or urine to check how well your kidneys are working.
Why might I need a creatinine test?
It helps check the health of your kidneys, diagnose kidney disease, monitor known kidney problems, and check for side effects from medicines that may affect your kidneys.
What does a high creatinine level mean?
A high level may be a sign of kidney disease or injury, but it can also be caused by dehydration, muscle disorders, intense exercise, or a diet high in meat.
What does a low creatinine level mean?
A low level may be a sign of malnutrition or muscle loss from aging, illness, or nerve disorders. Serious liver disease can also cause low levels.
Is a normal creatinine result a guarantee that my kidneys are healthy?
No. A normal result does not always mean your kidneys are healthy. Early kidney disease may not raise creatinine levels. Your provider may order other tests if they suspect a problem.
Related lab tests
Sources
- MedlinePlus: Creatinine Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.