24-Hour Urine Oxalate Excretion Rate

Why This Test Is Done

Your healthcare provider may recommend this test if you have a history of kidney stones, especially calcium oxalate stones, or if symptoms like pain in your side or back, blood in your urine, or frequent urination occur. It may also be used to monitor conditions like primary hyperoxaluria or other metabolic disorders that affect oxalate metabolism.

What to Expect Before the Test

You’ll need to collect all your urine for a full 24-hour period. Typically, you’ll start by emptying your bladder completely at the beginning of the test and then collect every drop of urine for the next 24 hours. Store the urine in a refrigerator or at room temperature in a sealed container. Bring the entire collection with you to your lab visit.

What Happens During the Test

No special preparation is needed beyond collecting your urine sample. The lab technician will analyze the collected urine to determine the amount of oxalate excreted over the 24-hour period.

What the Results Mean

Results are typically reported in milligrams (mg) of oxalate excreted per 24-hour urine sample. Higher than expected levels may suggest conditions like kidney stones, certain genetic disorders, or malabsorption issues. Lower levels might indicate metabolic or dietary factors affecting oxalate processing.