What is the Creatinine Clearance Test?

The creatinine clearance test is used to assess kidney function by examining urine and blood samples to determine the amount of creatinine, a waste substance that the kidneys filter out of the blood. The test is useful in identifying the presence of kidney disease or dysfunction.

The creatinine clearance test comprises two stages involving the collection of urine samples over 24 hours and the drawing blood. The samples are analyzed to determine the amount of creatinine filtered by the kidneys within the 24-hour. The test results are then used to calculate the creatinine clearance level, which estimates the glomerular filtration rate (GFR). The provider will utilize the GFR to establish how well the kidneys function

Creatinine Clearance Test Uses

The creatinine clearance test is performed to verify the kidney function level indicated by the eGFR measurement. Healthcare providers utilize this test to determine the effectiveness of the kidneys in performing their functions. The results of the test can aid in diagnosing kidney disease.

When does a Doctor Prescribe the Creatinine Clearance Test?

This test analyzes kidney function. While kidney disease can affect anyone, certain individuals are at higher risk. A specialist may prescribe it if you experience persistent symptoms, such as:

Here are some factors that doctors consider before prescribing a kidney function test:

Creatinine Clearance Test Results and Interpretation

The results of the creatinine clearance test provide valuable insights into kidney function.

Normal range

What do abnormal results mean?

Sometimes, the abnormal results from the creatinine clearance test can indicate various issues related to kidney function or other diseases.

Creatinine Clearance Test Preparation

The healthcare provider will provide detailed instructions before conducting the creatinine clearance test. The test involves collecting urine for 24 hours and drawing a blood sample.

The Doctor may also ask you to discontinue certain medications, if any. This is because some medications can impact the accuracy of the test results, so temporarily suspending their use may be necessary. These medications could include:

It is important to inform your healthcare provider of any medication you are taking and to ensure a comprehensive list of all medications is documented in your medical records.

Is it necessary to fast (not eat) before the creatinine clearance test?

Generally, there are no dietary restrictions before or during the creatinine clearance test. However, your healthcare provider may request that you refrain from eating overnight or abstain from consuming meat prior to the test. This is because meat contains higher levels of creatine, which can result in elevated creatinine levels during the test, leading to altered test results.

What Happens During the Creatinine Clearance Test?

You will do the creatinine clearance test over the course of 24 hours. During this time, you will collect your urine each time you urinate. This will give your healthcare provider a good idea of your creatinine levels throughout the day.

Regarding the creatinine clearance test, it is essential to follow the instructions provided by the healthcare provider strictly. These instructions will include directions for storing the urine sample and the location for submitting the sample once the test is completed.

Following the 24-hour urine collection, you will be required to have a blood draw to measure the creatinine level in the bloodstream, known as serum creatinine. The results from both the urine and blood tests will then be inputted into a mathematical formula to calculate the creatinine clearance. This rate informs the doctor about how effectively the kidneys filter waste from the bloodstream.