Protein — Normal Range & Interpretation

Clinical Context

Urine protein on dipstick screens for albumin excretion in the kidney. Healthy glomeruli retain protein, so a negative result confirms intact glomerular filtration. Any detectable protein warrants attention because proteinuria marks glomerular injury, tubular dysfunction, or systemic disease long before serum creatinine rises.

Nephrotic syndrome produces the heaviest proteinuria, often 3+ to 4+ on dipstick, paired with edema, hypoalbuminemia, and hyperlipidemia. Preeclampsia drives proteinuria after 20 weeks gestation alongside new hypertension. Urinary tract infection, orthostatic proteinuria in adolescents, strenuous exercise, fever, and diabetic nephropathy also produce positive results. Transient proteinuria resolves; persistent proteinuria on repeat testing requires quantification with a spot protein-to-creatinine ratio or 24-hour collection.

Classic AANP vignette: proteinuria as the hallmark finding in preeclampsia and nephrotic syndrome. Expect vignettes pairing proteinuria with facial edema in a child (minimal change disease) or with elevated blood pressure in a pregnant patient. Know that microalbuminuria screening in diabetes uses the albumin-to-creatinine ratio rather than standard dipstick, since dipstick misses low-level albumin excretion. Questions also distinguish benign orthostatic proteinuria in young adults from pathologic causes, and identify UTI as a reversible source of positive protein that clears after treatment.

Related Labs

• pH
• Specific Gravity
• Glucose
• WBC (urine) — /HPF
• RBC (urine) — /HPF

Sources

• MedlinePlus
• MedlinePlus