Urine protein excretion (24h)
What it measures, and what changes the number.
This test measures the total amount of protein passed in the urine over a full day. Rather than a single concentration from one sample, the lab multiplies the protein concentration by the total volume collected to give an amount per day.
It is usually read alongside the collected urine volume, the protein concentration from the same container, and creatinine measured in urine and blood. Creatinine helps confirm the collection was complete and allows creatinine clearance to be calculated. Blood albumin is often checked at the same time.
The result depends on a complete, correctly timed collection: discarding the first morning void, then saving every void through the next morning. Missed samples lower the figure. Exercise, fever and posture can also affect protein output. Spanish labs may print it as Proteinuria (Vol 24 horas).
Often read alongside: Urine volume (24h), Urine protein (24h), Creatinine clearance, Creatinine, Albumin