What does the Creatinine, Ur 24hr test measure?
A creatinine urine test measures the amount of creatinine — a byproduct of muscle movement and meat digestion — in the urine.
This test is done to see how well your kidneys are working — this is useful for diagnosing or ruling out kidney disease and other conditions affecting the kidneys.
If creatinine levels fall outside the normal range, this does not always signal a problem, but it can sometimes indicate an issue with the kidneys. If the results are abnormal, a doctor is likely to order additional tests to check for kidney issues.
Creatinine can also be measured by a blood test.
Your doctor may use a random urine sample to test for creatinine. However, they’ll order a urine 24-hour volume test in most cases. Although one sample of urine can be tested for creatinine, it’s more accurate to collect the urine for a whole day to get that value. The creatinine in your urine can vary a lot based on diet, exercise, and hydration levels, so a spot check is not as helpful. As the name suggests, this creatinine urine test measures the amount of urine produced in a day. It isn’t a painful test, and there aren’t any risks associated with it.
What exactly is Creatinine?
Creatinine is a chemical waste product of creatine, an amino acid made by the liver and stored in the liver. When your kidneys are functioning normally, they filter creatinine and other waste products out of your blood. These waste products are removed from your body through urination.
This process helps your body maintain a normal creatinine level. But sometimes, routine blood or urine tests can reveal low (or high) levels of creatinine.
Creatinine is a normal waste product that the body produces every day during muscle movements and when digesting meat. Healthy kidneys remove creatinine from the blood, and it leaves the body in urine.
There are natural variations in creatinine output due to age and body mass. The more muscular you are, the higher your range will be. It’s also important to note that not all laboratories use the same values. Results are dependent on the proper collection of your urine sample.
Normal urine creatinine values generally range from 955 to 2,936 milligrams (mg) per 24 hours for males, and 601 to 1,689 mg per 24 hours for females.
Abnormal results of urine creatinine may be due to any of the following:
→ High meat diet
→ Kidney problems, such as damage to the tubule cells
→ Kidney failure
→ Too little blood flow to the kidneys, causing damage to filtering units
→ Kidney infection (= pyelonephritis)
→ Muscle breakdown (rhabdomyolysis), or loss of muscle tissue (myasthenia gravis)
→ Urinary tract obstruction, such as kidney stones
→ Myasthenia gravis (a chronic autoimmune, neuromuscular disease that causes weakness in the skeletal muscles)
Abnormal values can also occur in people who have diabetes or a diet that’s high in meat or other proteins.
It’s very difficult to evaluate the test results on your own. You should discuss your results with your doctor.
Depending on your results, your doctor may order a serum creatinine test. This is a type of blood test that measures the amount of creatinine in your blood. Your doctor may use it to help confirm a diagnosis.
References:
Kalantari K, Bolton WK. A good reason to measure 24-hour urine creatinine excretion, but not to assess kidney function. Clin J Am Soc Nephrol. 2013 Nov;8(11):1847-9. doi: 10.2215/CJN.09770913. Epub 2013 Oct 24. PMID: 24158794; PMCID: PMC3817914.
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