Creatinine Clearance Test
Creatine phosphate in the muscle breaks down and produces creatine anhydrate (Creatinine) with the loss of water molecule. Creatinine enters blood and is transferred to the kidneys, where it is filtered out and excreted in the urine. However, if the kidneys do not function properly, the level of creatinine in the urine declines. Therefore, to evaluate kidney function and efficiency of filtration, the creatinine clearance test proves to be a very effective method.
Why is the test required?
The test may be helpful to evaluate kidney function and to detect the presence of kidney diseases. The test may also be used as a follow up test after an abnormal blood creatinine test and eGFR (Estimated glomerular filtration rate). It may also be used to monitor the progress of the disease in individuals with chronic kidney disease and congestive heart failure.
When is the test ordered?
The test may be ordered to evaluate the filtration ability of the kidneys and when kidney disease is suspected. Such signs and symptoms include-
- Decreased urine output
- Burning sensation
- Difficulty while urinating
- Blood or protein in the urine
- High blood pressure
- Change in the appearance of urine
- Puffiness around the eyes, face, abdomen, ankles
- Back pain
- Change in frequency of urination.
How is the sample collected?
A 24 hours urine sample is required for the test.
How to prepare for the test?
The person taking the test may be instructed to fast overnight or abstain from eating meat, in order to ensure correct results as eating cooked meat may elevate the creatinine levels in the body temporarily.