Protein urine

Random urine specimen or 24 h urine collection.

Spectrophotometry.

< 150 mg/24 h; pregnancy: < 250 mg/24 h.

Assessment of renal disease. Some methods will not detect light chain proteinuria; see Protein electrophoresis urine.

Protein loss in the urine is most commonly due to renal glomerular disease, esp if > 2 g/24 h. Proteinuria of > 3 g/24 h is required to establish the diagnosis of the Nephrotic syndrome. In renal tubular disease, light chain proteinuria, orthostatic proteinuria and myoglobinuria, protein loss is usually < 1 g/24 h.

See also Urinalysis.