Chronic Kidney Disease: Causes, Symptoms & Care Canada

Chronic kidney disease is a progressive condition in which the kidneys gradually lose their ability to filter waste and excess fluid from the blood. It affects an estimated 4 million Canadians, yet many remain undiagnosed until significant damage has already occurred. Early detection and proactive management with your healthcare provider are essential to slowing the disease and maintaining quality of life.

How Chronic Kidney Disease Develops and Progresses

Understanding the kidney disease causes, risk factors, and warning signs can empower you to take control of your kidney health Canada-wide. Whether you are living with diabetes, high blood pressure, or a family history of kidney problems, learning how CKD develops will help you work with your family doctor to create a care plan that protects your kidneys for the long term.

What Is Chronic Kidney Disease?

Stages of Chronic Kidney Disease: Characteristics and Management

Stage (eGFR mL/min/1.73m²)	Kidney Function	Common Symptoms	Management Approach
Stage 1 (≥90)	Normal or high function with signs of kidney damage	Usually none; may have protein in urine	Monitor blood pressure, manage underlying conditions (e.g., diabetes), annual eGFR testing
Stage 2 (60–89)	Mildly decreased function	Often no symptoms; mild fatigue possible	Lifestyle modifications, blood pressure control, reduce cardiovascular risk factors
Stage 3 (30–59)	Moderately decreased function	Fatigue, fluid retention, changes in urination, mild anaemia	Nephrology referral recommended, dietary adjustments (limit sodium, phosphorus), medication review
Stage 4 (15–29)	Severely decreased function	Nausea, swelling, shortness of breath, difficulty concentrating	Prepare for renal replacement therapy, dietitian support, discussion of dialysis or transplant options
Stage 5 (<15)	Kidney failure (end-stage renal disease)	Severe fatigue, confusion, little or no urine output, itching	Dialysis (hemodialysis or peritoneal) or kidney transplant; palliative care may be considered

Your kidneys are two small, bean-shaped organs that do very important work. Every day, they filter waste and extra fluid from your blood and remove them from your body as urine.

They also help keep the right balance of salts and minerals — called electrolytes — in your body. When the kidneys are damaged, waste builds up in the blood and makes you feel unwell.

Chronic kidney disease develops slowly over many years. It may seem to appear suddenly, but the damage builds up little by little. Each kidney contains about one million tiny filters called nephrons.

When nephrons are damaged, the healthy ones work harder to compensate. However, if damage continues, more and more nephrons stop working. Eventually, the kidneys can no longer do their job. According to Health Canada, kidney disease is a serious and growing public health concern across the country.

Common Causes of Chronic Kidney Disease

The causes of chronic kidney disease are not always clear. However, any condition that damages the blood vessels or structure of the kidneys can lead to kidney problems over time.

Diabetes

Diabetes is the leading cause of chronic kidney disease, responsible for about 35% of all cases in Canada. High blood sugar levels damage the tiny blood vessels inside the kidneys.

If blood sugar stays high over time, the kidneys gradually lose their ability to filter properly. Managing your blood sugar is one of the most important steps you can take to protect your kidneys.

High Blood Pressure

High blood pressure — also called hypertension — causes about 30% of all chronic kidney disease cases. It puts extra strain on the blood vessels in the kidneys, causing gradual damage.

Furthermore, kidney disease itself can raise blood pressure, creating a harmful cycle. This makes blood pressure control especially important for people already dealing with kidney problems.

Other Causes

In addition to diabetes and high blood pressure, other conditions can also damage the kidneys. These include:

• Polycystic kidney disease — a genetic condition where fluid-filled sacs grow in the kidneys
• Kidney infections — such as pyelonephritis (infection of the kidney tissue) or glomerulonephritis (inflammation of the kidney’s tiny blood vessels)
• Blocked or narrowed kidney arteries — reducing blood flow to the kidneys
• Kidney stones or an enlarged prostate — blocking normal urine flow
• Lead poisoning — long-term exposure to lead can harm kidney function
• Long-term use of certain medications — including regular use of pain relievers like acetaminophen or ibuprofen, and certain antibiotics. Always talk to your pharmacist or doctor before using any medication regularly.

Risk Factors for Chronic Kidney Disease

Some risk factors for chronic kidney disease cannot be changed. Others can be managed with healthy lifestyle choices. Knowing your risk factors helps you and your family doctor make a plan to protect your kidneys.

Risk Factors You Cannot Control

Certain factors increase your risk regardless of your lifestyle. These include:

• Age — Kidneys naturally shrink and lose function starting around age 35. By age 80, about 30% of kidney function may be lost.
• Family history — A family history of diabetes, high blood pressure, or inherited kidney diseases like polycystic kidney disease raises your risk significantly.
• Sex — Men are at a slightly higher risk of developing chronic kidney disease than women.
• Ethnicity — Some ethnic groups, including Black Canadians and South Asian Canadians, have a higher risk of kidney disease linked to higher rates of diabetes and high blood pressure.

Risk Factors You Can Control

The good news is that many risk factors are within your control. Making changes to your daily habits can slow the progress of kidney disease or even prevent it from starting. Controllable risk factors include:

• Uncontrolled high blood pressure — damages the tiny blood vessels in the kidneys over time
• Poorly managed diabetes — consistently high blood sugar accelerates kidney damage
• High protein and fat diet — a diet lower in protein and saturated fat helps reduce the workload on your kidneys
• Regular use of certain medications — avoid long-term, unsupervised use of non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin, and certain antibiotics
• Smoking — smoking damages blood vessels throughout the body, including those in the kidneys
• Physical inactivity and obesity — both increase the risk of diabetes and high blood pressure, which in turn harm the kidneys

Symptoms of Chronic Kidney Disease

One of the most challenging things about chronic kidney disease is that it often causes no symptoms in its early stages. This silent phase means many Canadians live with kidney damage for years without knowing it.

As the disease progresses and kidney function drops significantly, symptoms begin to appear. These can include:

• Reduced urine output — producing less urine than normal
• Swelling (oedema) — fluid builds up in the legs, ankles, or around the eyes
• Fatigue — feeling unusually tired, even after rest
• Loss of appetite or unexplained weight loss
• Nausea and vomiting
• Trouble sleeping or excessive daytime sleepiness
• Headaches or difficulty concentrating

Therefore, regular blood and urine tests are the only reliable way to catch kidney disease early. Your family doctor can order these tests as part of a routine check-up, especially if you have diabetes or high blood pressure.

How Chronic Kidney Disease Affects Your Body

When kidney disease is mild, the kidneys can still manage to keep fluid, salt, and waste in balance. However, as the condition worsens, complications begin to develop.

As more nephrons stop working, the kidneys lose their ability to remove waste effectively. Toxic waste products build up in the blood — a condition called uraemia. This affects almost every system in the body.

Complications of advancing chronic kidney disease can include:

• Anaemia — the kidneys produce less of a hormone called erythropoietin, which helps make red blood cells
• Bone disease — the kidneys help regulate calcium and phosphorus, so damage affects bone strength
• Heart disease — kidney disease significantly increases the risk of heart attack and stroke
• Fluid overload — fluid accumulates in the lungs and body tissues
• Kidney failure — at the most advanced stage, the kidneys stop working almost completely and dialysis or a kidney transplant becomes necessary

The good news is that slowing the progression of kidney disease is possible. Medication, dietary changes, and lifestyle adjustments — made in partnership with your healthcare team — can make a real difference. For more information, the Mayo Clinic’s guide to chronic kidney disease offers a helpful overview of treatment options.

When to See a Doctor

If you have diabetes, high blood pressure, or a family history of kidney disease, talk to your family doctor about getting your kidney function tested. A simple blood test (creatinine) and a urine test can detect early kidney disease before symptoms appear.

If you notice any of the symptoms listed above — such as swelling, unusual fatigue, or changes in your urine — do not wait. Visit your family doctor or a walk-in clinic as soon as possible.

In Canada, kidney function testing is covered under most provincial health plans when ordered by a physician. You do not need a specialist referral to get started — your family doctor is your first and most important resource. The World Health Organization’s fact sheet on chronic kidney disease also highlights the importance of early detection and regular screening.

Always speak with your doctor or a qualified healthcare professional before making any changes to your medications, diet, or treatment plan. This article is for informational purposes only and does not replace professional medical advice.

Frequently Asked Questions About Chronic Kidney Disease

Key Takeaways

• Chronic kidney disease is a long-term condition where the kidneys slowly lose their ability to filter waste from the blood.
• The two most common causes in Canada are diabetes and high blood pressure.
• The disease is often silent in early stages — regular testing is the only way to catch it early.
• Many risk factors — including blood sugar, blood pressure, diet, and medication use — can be managed to slow kidney damage.
• Symptoms such as swelling, fatigue, nausea, and reduced urine output appear as the disease advances.
• Kidney function testing is available through your family doctor or walk-in clinic and is covered by most provincial health plans.
• Always consult your doctor before changing your diet, medications, or treatment routine.