Oxalate in Urine (24-hour collection)

Why This Test Is Done

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

What to Expect Before the Test

You’ll need to collect all urine for a full 24-hour period, typically starting after you wake up in the morning and continuing until you wake up again the next morning. Empty your bladder before starting and discard that urine. Collect every urine sample in a container provided by your lab. Store the samples at room temperature and return them to the lab on the same day.

What to Expect During the Test

No special preparation is needed beyond the 24-hour urine collection. You’ll likely be given a container to use and instructions on how to properly collect and store your urine samples.

What the Results Mean

Higher than expected oxalate levels may suggest conditions that increase oxalate production or reduce its excretion, such as certain dietary habits, metabolic disorders, or kidney issues. Lower levels may indicate malabsorption or other underlying health concerns. Your results will be reviewed by your healthcare provider to determine if further testing or changes in treatment are needed.