24-Hour Urine Protein
This test measures the total amount of protein your kidneys release into the urine over a full 24 hours. You collect all your urine during the day to capture the true daily amount, smoothing out hour-to-hour variation.
A 24-hour collection has long been a reference standard for measuring protein loss and assessing kidney function. It helps detect and monitor kidney disease and conditions like pregnancy-related high blood pressure, though spot-sample ratios are increasingly used for convenience.
More protein than expected over 24 hours (proteinuria) can indicate the kidney's filters are leaking, which may relate to kidney disease, diabetes, high blood pressure, or other conditions. The amount helps your clinician judge severity and guide further evaluation.
A low daily protein amount is normal and suggests the kidneys are keeping protein where it belongs, in the blood.
Losing less than about 150 mg of protein per day is generally considered normal, with results depending on the lab and your situation. Because collection errors are common, your clinician may confirm findings with repeat or spot-sample testing.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.