If you’ve recently had blood work or urine testing performed, you may have seen terms such as creatinine, eGFR, albumin, proteinuria, or kidney function on your laboratory report. Many patients across British Columbia receive kidney-related test results without fully understanding what these numbers mean.

This guide explains the most common kidney laboratory tests, why they matter, and when you should consider speaking with a nephrologist. Whether you have chronic kidney disease (CKD), diabetes, high blood pressure, or simply want to better understand your health, knowing how to interpret your kidney lab work can help you take a more active role in your care.

Why Kidney Lab Tests Matter

Your kidneys perform several essential functions, including:

• Removing waste products from the blood
• Maintaining fluid balance
• Regulating blood pressure
• Balancing electrolytes
• Supporting healthy red blood cell production
• Maintaining bone health

When kidney function begins to decline, laboratory testing is often the earliest way to identify a problem.

The Most Important Kidney Blood Tests

Serum Creatinine

Creatinine is one of the most commonly ordered kidney blood tests. It is a waste product produced by normal muscle activity and is filtered by the kidneys.

When kidney function declines, creatinine levels may rise because the kidneys are no longer removing it efficiently.

A single elevated creatinine result does not automatically mean you have kidney disease. Your nephrologist will consider factors such as age, sex, muscle mass, medications, and overall health.

Estimated Glomerular Filtration Rate (eGFR)

The eGFR is one of the most important measurements used to evaluate kidney function.

This calculation estimates how effectively your kidneys filter waste products from your blood.

Generally:

• eGFR 90 or higher is usually considered normal
• eGFR 60–89 may indicate mild kidney impairment in some patients
• eGFR below 60 for more than three months may suggest chronic kidney disease
• Lower values indicate more advanced kidney dysfunction

Many patients in British Columbia are referred to a nephrologist after an abnormal eGFR result.

Blood Urea Nitrogen (BUN)

BUN measures the amount of urea nitrogen in the blood.

Elevated levels may occur because of:

• Reduced kidney function
• Dehydration
• High protein intake
• Certain medications

This test is usually interpreted alongside creatinine and eGFR.

Understanding Urine Tests

Urine Albumin-to-Creatinine Ratio (ACR)

The ACR test measures the amount of albumin leaking into the urine.

Healthy kidneys normally prevent significant protein loss.

Elevated albumin levels may indicate:

• Early diabetic kidney disease
• Chronic kidney disease
• High blood pressure-related kidney damage

This is one of the most important tests for patients living with diabetes.

Proteinuria

Proteinuria means excess protein is present in the urine.

Persistent proteinuria may be an early sign of kidney disease, even when kidney function appears normal.

Protein in the urine often requires further investigation by a kidney specialist.

Hematuria

Hematuria refers to blood in the urine.

Potential causes include:

• Kidney stones
• Urinary tract infections
• Kidney inflammation
• Structural kidney abnormalities

Not all cases are serious, but persistent blood in the urine should be evaluated.

Important Electrolytes and Kidney Health

Potassium

Potassium helps regulate muscle and heart function.

When kidney function declines, potassium levels may rise and require medical attention.

Sodium

Sodium helps maintain fluid balance and blood pressure.

Abnormal sodium levels can occur in certain kidney disorders.

Bicarbonate

Bicarbonate helps maintain the body’s acid-base balance.

Advanced kidney disease may reduce bicarbonate levels, resulting in metabolic acidosis.

Kidney Lab Work and Diabetes

Diabetes is one of the leading causes of kidney disease in Canada.

Patients with diabetes should routinely monitor:

• eGFR
• Creatinine
• Urine ACR
• Blood pressure
• Blood sugar control

Early detection of diabetic kidney disease can help slow progression and reduce complications.

Kidney Lab Work and High Blood Pressure

High blood pressure can both cause and result from kidney disease.

Patients with hypertension often require periodic monitoring of:

• Kidney function
• Electrolytes
• Urine protein levels

Effective blood pressure control is one of the most important ways to protect kidney health.

When Should You See a Nephrologist?

You should consider a nephrology consultation if you have:

• Persistent protein in your urine
• Blood in your urine
• Declining eGFR
• Elevated creatinine levels
• Chronic kidney disease
• Resistant high blood pressure
• Diabetic kidney disease
• Recurrent kidney stones
• Abnormal kidney imaging results

Early referral can often help slow disease progression and improve long-term outcomes.

Chronic Kidney Disease Stages Explained

Stage 1 CKD

Kidney damage with normal or near-normal kidney function.

Stage 2 CKD

Mild reduction in kidney function.

Stage 3 CKD

Moderate reduction in kidney function requiring closer monitoring.

Stage 4 CKD

Severe reduction in kidney function.

Stage 5 CKD

Kidney failure requiring specialized management and potential discussion regarding dialysis or transplantation.

How Often Should Kidney Lab Work Be Checked?

Monitoring frequency varies depending on your condition.

Patients with:

• Diabetes
• High blood pressure
• Chronic kidney disease
• Family history of kidney disease

may require regular laboratory testing to monitor kidney health.

Virtual Nephrology Consultations in British Columbia

Many kidney-related concerns can be discussed through virtual nephrology consultations.

Patients can review:

• Blood work
• Urine test results
• Kidney imaging reports
• Medication concerns
• Chronic kidney disease management plans

Virtual consultations provide convenient access to nephrology expertise for patients throughout British Columbia.

Final Thoughts

Understanding your kidney laboratory results can help you become a more informed participant in your healthcare journey. While laboratory values provide valuable information, they should always be interpreted within the context of your overall health, medical history, symptoms, and risk factors.

If you have concerns about abnormal kidney blood work, declining kidney function, protein in your urine, or diabetic kidney disease, speaking with a nephrologist can help clarify your results and determine the most appropriate next steps.