Protein in the Urine: What It Signals
Why protein leaks into urine and what proteinuria means for kidney health.
Last updated: 2026-09-24
Protein in the urine (proteinuria) is an early and important sign of kidney damage — healthy kidneys retain protein in the blood.
Common causes
- Diabetes and high blood pressure
- Glomerulonephritis
- Urinary infection
- Temporary causes such as fever or strenuous exercise
Frequently asked questions
Can proteinuria be reversed?
With treatment of the underlying cause, protein leak often improves.