Protein in Urine (Proteinuria)
Protein leaking into urine is an early, important signal from your kidneys. Caught early, the underlying cause can often be treated effectively.
Medically reviewed by the RIIMS nephrology team · Last updated: June 2026
Why does protein appear in urine?
Healthy kidney filters are fine enough to keep protein in the blood; when they are inflamed or damaged (by diabetes, blood pressure, infections or a kidney-specific disease), albumin and other proteins leak into the urine. Albuminuria is often the earliest sign of kidney damage, appearing while creatinine still looks normal, so it should never be dismissed. Urine tests (ACR, 24-hour protein) read alongside eGFR show how significant the leak is and what is driving it.
Symptoms to watch for
- Foamy or frothy urine
- Puffiness around the eyes, worse in mornings
- Swelling in feet or ankles
- Weight gain from fluid
- Often none, found only on routine urine tests
- Higher risk with diabetes or high BP
When to consult a kidney doctor
Persistent foamy urine, morning facial puffiness, or protein flagged on any routine test deserves timely evaluation, especially if you have diabetes or hypertension.