Type

Urine

Part of

Urinalysis

Part of

Urinalysis

Blood biomarker

Part of

Urinalysis

Protein (Urine)

Protein in urine, also known as proteinuria, indicates excess protein filtration by the kidneys.

Protein (Urine)

Normal range

Negative

Normal range

Negative

Normal range

Protein (Urine)

Protein in urine, also known as proteinuria, indicates excess protein filtration by the kidneys.

Protein (Urine)

Normal range

Negative

Normal range

Negative

Normal range

Protein (Urine)

Protein in urine, also known as proteinuria, indicates excess protein filtration by the kidneys.

Protein (Urine)

Normal range

Negative

Normal range

Negative

Normal range

Protein (Urine)

Dr. Daniel McNally

MBBS

The Kidney Filter Check

Protein in your urine is like a leak in your body's filtration system - it indicates that your kidneys may not be filtering your blood as effectively as they should. While tiny amounts of protein in urine can be normal, higher levels often signal kidney damage or disease that needs medical attention.

Your kidneys act like sophisticated filters, keeping useful proteins in your blood whilst removing waste products. When protein appears in significant amounts in your urine, it suggests these filters have developed "holes" that allow protein to escape where it shouldn't.

Get tested

Why Protein Leaks Into Your Urine

Discover what kidney conditions and diseases cause protein to escape from your blood into your urine.

When Protein in Urine Signals Problems

Learn about the kidney diseases and systemic conditions that cause dangerous protein loss through urine.

Temporary vs. Persistent Protein in Urine

Find out about harmless causes of protein in urine versus concerning patterns that need medical investigation.

Understanding Your Results

Understand how doctors interpret protein levels and what additional tests might be needed.

Why Protein Leaks Into Your Urine

Protein in urine, called proteinuria, occurs when your kidney's filtering system becomes damaged or overwhelmed, allowing proteins that should remain in your blood to leak into your urine.

Normal kidney function: Healthy kidneys filter about 180 litres of blood daily, removing waste whilst retaining useful proteins like albumin. The filtering units (glomeruli) have barriers that prevent most proteins from passing through.
Filter damage: When kidney filters become damaged by disease, inflammation, or other conditions, they develop "leaks" that allow proteins to escape. This is similar to a coffee filter developing holes that let coffee grounds through.
Protein size matters: Smaller proteins may leak through mildly damaged filters, whilst larger proteins indicate more significant kidney damage. Albumin, being moderately sized, serves as an excellent marker for early kidney problems.
Disease progression: As kidney disease advances, more protein leaks into urine. This protein loss can worsen kidney damage and contribute to swelling and other health issues.

Why Protein Leaks Into Your Urine

Protein in urine, called proteinuria, occurs when your kidney's filtering system becomes damaged or overwhelmed, allowing proteins that should remain in your blood to leak into your urine.

Normal kidney function: Healthy kidneys filter about 180 litres of blood daily, removing waste whilst retaining useful proteins like albumin. The filtering units (glomeruli) have barriers that prevent most proteins from passing through.
Filter damage: When kidney filters become damaged by disease, inflammation, or other conditions, they develop "leaks" that allow proteins to escape. This is similar to a coffee filter developing holes that let coffee grounds through.
Protein size matters: Smaller proteins may leak through mildly damaged filters, whilst larger proteins indicate more significant kidney damage. Albumin, being moderately sized, serves as an excellent marker for early kidney problems.
Disease progression: As kidney disease advances, more protein leaks into urine. This protein loss can worsen kidney damage and contribute to swelling and other health issues.

Why Protein Leaks Into Your Urine

Protein in urine, called proteinuria, occurs when your kidney's filtering system becomes damaged or overwhelmed, allowing proteins that should remain in your blood to leak into your urine.

Normal kidney function: Healthy kidneys filter about 180 litres of blood daily, removing waste whilst retaining useful proteins like albumin. The filtering units (glomeruli) have barriers that prevent most proteins from passing through.
Filter damage: When kidney filters become damaged by disease, inflammation, or other conditions, they develop "leaks" that allow proteins to escape. This is similar to a coffee filter developing holes that let coffee grounds through.
Protein size matters: Smaller proteins may leak through mildly damaged filters, whilst larger proteins indicate more significant kidney damage. Albumin, being moderately sized, serves as an excellent marker for early kidney problems.
Disease progression: As kidney disease advances, more protein leaks into urine. This protein loss can worsen kidney damage and contribute to swelling and other health issues.

When Protein in Urine Signals Problems

Significant protein in urine often indicates kidney disease or systemic conditions that can cause serious health complications if left untreated.

Diabetic kidney disease: Diabetes is the leading cause of kidney disease, and protein in urine is often the first sign of diabetic kidney damage. Early detection and treatment can slow progression and prevent kidney failure.
High blood pressure damage: Chronic high blood pressure can damage kidney blood vessels, leading to protein leakage. This creates a vicious cycle where kidney damage worsens blood pressure control.
Glomerulonephritis: This condition involves inflammation of your kidney's filtering units, causing protein to spill into your urine. It can develop from infections, autoimmune diseases (where your immune system attacks your own tissues), or other inflammatory conditions.
Nephrotic syndrome: This serious condition involves massive protein loss (over 3.5 grams daily), leading to severe swelling, low blood protein levels, and increased infection risk. It requires immediate medical intervention.
Autoimmune diseases: Conditions like lupus can attack your kidney filters, causing protein leakage along with other kidney problems. Early detection and treatment can help prevent further damage to your kidneys.
Kidney infections: Severe kidney infections can temporarily increase protein in urine, though this usually resolves with appropriate antibiotic treatment.

When Protein in Urine Signals Problems

Significant protein in urine often indicates kidney disease or systemic conditions that can cause serious health complications if left untreated.

Diabetic kidney disease: Diabetes is the leading cause of kidney disease, and protein in urine is often the first sign of diabetic kidney damage. Early detection and treatment can slow progression and prevent kidney failure.
High blood pressure damage: Chronic high blood pressure can damage kidney blood vessels, leading to protein leakage. This creates a vicious cycle where kidney damage worsens blood pressure control.
Glomerulonephritis: This condition involves inflammation of your kidney's filtering units, causing protein to spill into your urine. It can develop from infections, autoimmune diseases (where your immune system attacks your own tissues), or other inflammatory conditions.
Nephrotic syndrome: This serious condition involves massive protein loss (over 3.5 grams daily), leading to severe swelling, low blood protein levels, and increased infection risk. It requires immediate medical intervention.
Autoimmune diseases: Conditions like lupus can attack your kidney filters, causing protein leakage along with other kidney problems. Early detection and treatment can help prevent further damage to your kidneys.
Kidney infections: Severe kidney infections can temporarily increase protein in urine, though this usually resolves with appropriate antibiotic treatment.

When Protein in Urine Signals Problems

Significant protein in urine often indicates kidney disease or systemic conditions that can cause serious health complications if left untreated.

Diabetic kidney disease: Diabetes is the leading cause of kidney disease, and protein in urine is often the first sign of diabetic kidney damage. Early detection and treatment can slow progression and prevent kidney failure.
High blood pressure damage: Chronic high blood pressure can damage kidney blood vessels, leading to protein leakage. This creates a vicious cycle where kidney damage worsens blood pressure control.
Glomerulonephritis: This condition involves inflammation of your kidney's filtering units, causing protein to spill into your urine. It can develop from infections, autoimmune diseases (where your immune system attacks your own tissues), or other inflammatory conditions.
Nephrotic syndrome: This serious condition involves massive protein loss (over 3.5 grams daily), leading to severe swelling, low blood protein levels, and increased infection risk. It requires immediate medical intervention.
Autoimmune diseases: Conditions like lupus can attack your kidney filters, causing protein leakage along with other kidney problems. Early detection and treatment can help prevent further damage to your kidneys.
Kidney infections: Severe kidney infections can temporarily increase protein in urine, though this usually resolves with appropriate antibiotic treatment.

Temporary vs. Persistent Protein in Urine

Understanding the difference between transient and ongoing proteinuria helps distinguish harmless fluctuations from concerning patterns.

Temporary causes: Fever, intense exercise, dehydration, stress, or standing for long periods can temporarily increase protein in urine. These typically resolve once the underlying cause is addressed.
Orthostatic proteinuria: Benign proteinuria occurring only when standing, most common in adolescents, resolves without treatment.
Pregnancy considerations: Mild protein increases can occur during normal pregnancy, but higher levels may indicate preeclampsia, a serious condition requiring immediate medical attention.
Medication effects: Certain medications, including some antibiotics and pain relievers, can temporarily increase protein in urine. This typically resolves after stopping the medication.
Persistent patterns: Proteinuria detected in multiple samples over weeks to months suggests underlying kidney disease and warrants further evaluation.

Doctors focus on persistent protein patterns rather than isolated findings, using repeated testing to distinguish between temporary fluctuations and kidney problems.

Temporary vs. Persistent Protein in Urine

Understanding the difference between transient and ongoing proteinuria helps distinguish harmless fluctuations from concerning patterns.

Temporary causes: Fever, intense exercise, dehydration, stress, or standing for long periods can temporarily increase protein in urine. These typically resolve once the underlying cause is addressed.
Orthostatic proteinuria: Benign proteinuria occurring only when standing, most common in adolescents, resolves without treatment.
Pregnancy considerations: Mild protein increases can occur during normal pregnancy, but higher levels may indicate preeclampsia, a serious condition requiring immediate medical attention.
Medication effects: Certain medications, including some antibiotics and pain relievers, can temporarily increase protein in urine. This typically resolves after stopping the medication.
Persistent patterns: Proteinuria detected in multiple samples over weeks to months suggests underlying kidney disease and warrants further evaluation.

Doctors focus on persistent protein patterns rather than isolated findings, using repeated testing to distinguish between temporary fluctuations and kidney problems.

Temporary vs. Persistent Protein in Urine

Understanding the difference between transient and ongoing proteinuria helps distinguish harmless fluctuations from concerning patterns.

Temporary causes: Fever, intense exercise, dehydration, stress, or standing for long periods can temporarily increase protein in urine. These typically resolve once the underlying cause is addressed.
Orthostatic proteinuria: Benign proteinuria occurring only when standing, most common in adolescents, resolves without treatment.
Pregnancy considerations: Mild protein increases can occur during normal pregnancy, but higher levels may indicate preeclampsia, a serious condition requiring immediate medical attention.
Medication effects: Certain medications, including some antibiotics and pain relievers, can temporarily increase protein in urine. This typically resolves after stopping the medication.
Persistent patterns: Proteinuria detected in multiple samples over weeks to months suggests underlying kidney disease and warrants further evaluation.

Doctors focus on persistent protein patterns rather than isolated findings, using repeated testing to distinguish between temporary fluctuations and kidney problems.

Get started

Understanding Your Results

Understanding protein test interpretation helps you better comprehend what your results indicate and what steps might follow.

Normal (Negative): No detectable protein—your kidneys are filtering normally.
Trace (+): Trace protein—may occur after exercise or fever; trace levels alone usually prompt monitoring without causing concern.
+1 (0–64 mg/dL): Mild proteinuria—could indicate early kidney stress, especially in diabetes or hypertension; warrants follow‑up.
+2 (65–199 mg/dL): Moderate proteinuria—suggests more significant glomerular damage; requires further correlation with other tests and associate to any known causes.
+3 (200–1149 mg/dL) or +4 (≥ 1150 mg/dL): Heavy proteinuria— signifies a high amount of protein loss and should be supervised by doctor for a known condition or a new diagnosis that requires investigation.

To confirm and monitor, doctors may order a 24‑hour urine collection, a urine protein‑to‑creatinine ratio (PCR) or albumin-to-creatinine ratio (ACR), which more precisely measure protein loss, and are the gold standard for assessing evidence of kidney damage.In known kidney disease, regular protein testing assesses treatment effectiveness and disease progression.

Understanding Your Results

Understanding protein test interpretation helps you better comprehend what your results indicate and what steps might follow.

Normal (Negative): No detectable protein—your kidneys are filtering normally.
Trace (+): Trace protein—may occur after exercise or fever; trace levels alone usually prompt monitoring without causing concern.
+1 (0–64 mg/dL): Mild proteinuria—could indicate early kidney stress, especially in diabetes or hypertension; warrants follow‑up.
+2 (65–199 mg/dL): Moderate proteinuria—suggests more significant glomerular damage; requires further correlation with other tests and associate to any known causes.
+3 (200–1149 mg/dL) or +4 (≥ 1150 mg/dL): Heavy proteinuria— signifies a high amount of protein loss and should be supervised by doctor for a known condition or a new diagnosis that requires investigation.

Understanding Your Results

Understanding protein test interpretation helps you better comprehend what your results indicate and what steps might follow.

Normal (Negative): No detectable protein—your kidneys are filtering normally.
Trace (+): Trace protein—may occur after exercise or fever; trace levels alone usually prompt monitoring without causing concern.
+1 (0–64 mg/dL): Mild proteinuria—could indicate early kidney stress, especially in diabetes or hypertension; warrants follow‑up.
+2 (65–199 mg/dL): Moderate proteinuria—suggests more significant glomerular damage; requires further correlation with other tests and associate to any known causes.
+3 (200–1149 mg/dL) or +4 (≥ 1150 mg/dL): Heavy proteinuria— signifies a high amount of protein loss and should be supervised by doctor for a known condition or a new diagnosis that requires investigation.

The Takeaway

Proteinuria is an important early warning for kidney disease and systemic conditions. While temporary increases can occur with exercise or illness, persistent or high levels of urinary protein warrant medical evaluation to identify and treat underlying causes.

Early detection and treatment of kidney disease can slow progression and prevent complications like kidney failure, heart disease, and stroke. Regular monitoring is particularly important for people with diabetes, high blood pressure, or family history of kidney disease.

Don't ignore protein in urine, especially if you have risk factors for kidney disease, such as high blood pressure or diabetes.

The Takeaway

Don't ignore protein in urine, especially if you have risk factors for kidney disease, such as high blood pressure or diabetes.

The Takeaway

Don't ignore protein in urine, especially if you have risk factors for kidney disease, such as high blood pressure or diabetes.

References

National Institute for Health and Care Excellence. (2018). Kidney stones: assessment and management. NICE Clinical Guideline.
British Association of Urological Surgeons. (2020). Guidelines for metabolic stone disease. BAUS Clinical Guidelines.
Kidney Research UK. (2019). Urine analysis and kidney function assessment. Clinical Practice Guidelines.

References

National Institute for Health and Care Excellence. (2018). Kidney stones: assessment and management. NICE Clinical Guideline.
British Association of Urological Surgeons. (2020). Guidelines for metabolic stone disease. BAUS Clinical Guidelines.
Kidney Research UK. (2019). Urine analysis and kidney function assessment. Clinical Practice Guidelines.

References

National Institute for Health and Care Excellence. (2018). Kidney stones: assessment and management. NICE Clinical Guideline.
British Association of Urological Surgeons. (2020). Guidelines for metabolic stone disease. BAUS Clinical Guidelines.
Kidney Research UK. (2019). Urine analysis and kidney function assessment. Clinical Practice Guidelines.