Creatinine, 24-Hour Urine



Quest Diagnostics Test Code: 381

Blood creatinine level is measured as a test of kidney function to estimate the glomerular filtration rate (GFR), the rate of blood flow through the kidneys.

Creatinine is a waste product that is produced by the muscles during energy production and respiration and is removed by the kidneys, which filters almost all of it from the blood to be excreted in the urine. Creatinine is one of the most important tests used to determine kidney function. Creatinine measurement is needed to calculate other kidney function tests, such as creatinine clearance and glomerular filtration rate. High levels of creatinine most certainly point to a kidney problem, and along with other kidney tests can help in the diagnosis of specific kidney disease of diseases which eventually affect the kidneys, such as diabetes and high blood pressure. The most accurate measurement of creatinine is a 24-hour urine collection

This test is performed in following conditions such as:

• Fatigue, lack of concentration, poor appetite, or trouble sleeping
• Swelling or edema
• Abnormal urine color
• A decrease in the amount of urine
• Burning or pain on urination
• Mid back pain
• High blood pressure


The Creatinine, 24-hour Urine test requires people void urine at 8am and discard the specimen. Then collect all urine in 24-hour period, ending with final collection at 8am the next morning.


Specimen Collected
  • Urine
Estimated Time Taken

Turnaround time for the Creatinine, 24-hour Urine test is typically 1 business day.