Stages of Kidney Disease Explained
Chronic kidney disease (CKD) is a long-term kidney condition that causes gradual loss of kidney function, which removes waste, excess fluid, and toxins from the blood. This decrease occurs over months or years, so many people don't notice any symptoms in the early stages.
Chronic kidney disease is divided into several stages, each indicating a specific level of kidney function and therefore a corresponding treatment and care approach.
Read on to explore the chronic kidney disease progression and what each stage means for your kidney health.
What are the 5 Stages of Chronic Kidney Disease?
Chronic kidney disease (CKD) can be classified into five stages according to the ability of the kidneys to remove waste products from the blood. Blood and urine tests are used to detect the stage of CKD.
The stages range from Stage 1 (mild kidney damage) to Stage 5 (kidney failure). The classification is determined by your glomerular filtration rate (GFR), which measures how well your kidneys are filtering blood. GFR is calculated using the level of creatinine, a waste product found in the bloodstream.
| Stage | GFR (mL/min) | What It Means |
| Stage 1 | 90 and above | Your kidneys are functioning normally, but there are early signs of mild kidney damage. |
| Stage 2 | 60–89 | Kidney function remains good, although additional evidence of mild kidney damage is present. |
| Stage 3a | 45–59 | Kidney function has declined to a mild-to-moderate level. This is the most commonly diagnosed stage, and symptoms may begin to appear. |
| Stage 3b | 30–44 | Moderate kidney damage is present, and kidney function is further reduced. With appropriate treatment, many people remain at this stage without progressing to Stage 4. |
| Stage 4 | 15–29 | Kidney function is severely reduced, and the kidneys are close to failing. |
| Stage 5 | Less than 15 | The kidneys have nearly or completely stopped working. Dialysis or a kidney transplant may be required at this stage. |
Stage 1 Kidney Disease
Stage 1 CKD is defined by an eGFR ≥90 mL/min/1.73 m² together with evidence of kidney damage, such as albuminuria or structural kidney abnormalities. Because the kidneys can compensate for mild damage, they usually continue performing their normal functions.
This stage may be discovered randomly on a routine blood or urine test. People with conditions such as diabetes or high blood pressure, the leading causes of CKD, are more likely to undergo these screening tests.
Symptoms
Most people do not experience any symptoms while kidney function remains at 90% or above.
Treatment
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD) suggests the following to help slow the progression of CKD:
- If you have diabetes, maintain a healthy blood sugar level.
- Control high blood pressure in case of hypertension.
- Eat a healthy and balanced diet.
- Avoid tobacco use.
- Get a good night's sleep (7-8 hours).
- Reduce stress and anxiety through relaxation techniques.
- Stay physically active for at least 30 minutes a day, five days a week.
- Keep a healthy weight.
Your healthcare provider may also refer you to a nephrologist (kidney specialist) for more specialist advice.
Stage 2 Kidney Disease
Stage 2 CKD is characterized by an eGFR of 60-89 mL/min/1.73 m² along with evidence of kidney damage.
Symptoms
There are many people who don't show any symptoms. When chronic kidney disease symptoms do occur, they are often general and may include:
- High blood pressure
- Swelling in the hands and feet
- Blood in the urine
Treatment
Although CKD cannot be cured, early treatment and lifestyle changes can significantly slow or even prevent further progression. Managing the underlying cause of kidney disease is essential. This involves managing diabetes, hypertension, or heart disease.
If fatigue becomes a concern, adopting healthy daily habits and lifestyle adjustments may help improve energy levels.
Stage 3 Kidney Disease
Stage 3A CKD occurs when kidney function falls between 45–59%, while Stage 3B CKD is defined by kidney function between 30–44%. Kidney function is moderately reduced at this stage, and some individuals may begin to experience complications related to decreased filtration.
According to the National Kidney Foundation (NKF), this is the stage when many people first receive a CKD diagnosis because an estimated glomerular filtration rate (eGFR) blood test can clearly detect reduced kidney function.
Symptoms
Some people may still have no symptoms, while others may experience:
- Back pain
- Fatigue
- Loss of appetite
- Persistent itching
- Sleep problems
- Swelling in the hands and feet
- Urinating more or less than usual
- Weakness
Possible complications include:
- Anemia
- Bone disease
- High blood pressure
Treatment
Your healthcare provider might suggest dietary changes such as cutting back on:
- Sodium
- Calcium
- Potassium
- Phosphate
Controlling underlying health conditions is still essential to maintain kidney function. Treatment may include:
- Medications that treat blood pressure, including angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs)
- Diuretics to reduce fluid retention
- Cholesterol-lowering medications
- Erythropoietin supplements to treat anaemia
A healthcare provider may also recommend discontinuing some medicines, such as nonsteroidal anti-inflammatory drugs (NSAIDs). Follow-up appointments and routine testing may be needed to adapt your treatment plan to the changing patterns of your disease.
Stage 4 Kidney Disease
Stage 4 CKD is characterized by severely decreased kidney function with an eGFR of 15-29 mL/min/1.73 m². The kidneys function poorly at this stage to excrete wastes, toxins, and excess fluids, resulting in a buildup of these substances in the body.
At this phase, prevention of the disease from reaching the stage of kidney failure is a key concern. According to the Centres for Disease Control and Prevention (CDC), nearly 40% of people with severely reduced kidney function are unaware that they have CKD.
Symptoms
Symptoms may include:
- Back pain
- Chest pain
- Reduced mental clarity
- Fatigue
- Loss of appetite
- Muscle spasms or cramps
- Nausea and vomiting
- Persistent itching
- Shortness of breath
- Sleep disturbances
- Swelling of hands and feet
- Urinating more or less than usual
- Weakness
- Weight loss
Complications may include:
- Anemia
- Bone disease
- High blood pressure
People at this stage also have a higher risk of developing heart disease and stroke.
Treatment
During Stage 4 CKD, it is essential to work closely with your healthcare team to monitor kidney function and manage complications. It is also a time to start talking about other options for treatment if the kidneys fail, including dialysis and a kidney transplant.
Stage 4 CKD may also cause other health issues that need to be treated. One common complication is metabolic acidosis. Your healthcare provider may prescribe oral bicarbonate replacement, depending on your blood bicarbonate level.
Stage 5 Kidney Disease
Stage 5 CKD is defined by an eGFR below 15 mL/min/1.73 m² or the need for kidney replacement therapy.
Waste products and toxins now accumulate to toxic levels, making this very life-threatening. This stage can be called end-stage renal disease (ESRD).
Symptoms
Kidney failure can be accompanied by the following symptoms:
- Back and chest pain
- Breathing difficulties
- Confusion and trouble concentrating
- Weight loss
- Fatigue
- Little or no appetite
- Muscle twitching or cramps
- Nausea or vomiting
- Persistent itching
- Difficulty sleeping
- Severe weakness
- Puffy hands and feet
- Urinating more or less than usual
Also, lower kidney function increases pressure on the heart and can lead to an increased risk of heart disease and stroke.
Treatment
Without dialysis or kidney transplantation, survival in advanced kidney failure varies considerably between individuals and depends on several clinical factors.
Although dialysis is not a cure for CKD, it allows excess waste and fluid to be removed from the bloodstream. Hemodialysis and peritoneal dialysis are the two major types of dialysis.
Hemodialysis
Hemodialysis can be done in a dialysis centre or at home. Typically, treatment at a dialysis centre is held about three times a week. With proper training, many people can safely perform hemodialysis at home. However, this requires a surgical procedure to create a suitable access point in a vein.
Home hemodialysis is often performed more frequently but for shorter treatment sessions, allowing greater flexibility based on individual needs. During each session, two needles are inserted into the access site. These are connected to a dialyser, often called an artificial kidney. Blood flows through the machine to be filtered and then returned to the body.
- Peritoneal dialysis
For peritoneal dialysis, a surgeon places a catheter into the abdomen. During treatment, a dialysis solution flows through the catheter into the abdominal cavity. You can continue your normal activities while the solution remains inside your abdomen.
After several hours, the solution is drained into a collection bag and discarded. This process must be repeated several times each day.
A kidney transplant replaces the damaged kidney with a healthy kidney from either a living or deceased donor. Following a successful transplant, dialysis is no longer necessary, but lifelong anti-rejection medication is required to help prevent the body from rejecting the new kidney.
Conclusion
There are 5 stages of chronic kidney disease, and each is identified by blood and urine tests and the amount of kidney damage. While CKD is a progressive condition, not all people with CKD will develop kidney failure.
The early chronic kidney disease stages are often asymptomatic and can be easily missed. For this reason, regular health checkups are especially important for people with diabetes or high blood pressure, the two leading causes of kidney disease.
Early detection and prompt treatment of underlying diseases can help to slow the progression of CKD or to prevent it from worsening.
Reader Information: This article is intended for informational and educational purposes only and should not be considered medical advice, diagnosis, or treatment. Chronic kidney disease (CKD) staging, symptoms, and treatment decisions vary from person to person. Always consult a qualified healthcare professional or nephrologist for advice regarding your specific medical condition. In case of severe symptoms or a medical emergency, seek immediate medical attention.
FAQs
How long can you live with kidney failure?
Life expectancy for people with CKD varies widely and is difficult to predict. While kidney disease generally shortens life expectancy, factors such as a person's age at diagnosis, overall health, and the treatment they receive all play an important role in determining outcomes.
At what stage of CKD do you need dialysis?
Dialysis is typically required during Stage 5 CKD, also known as end-stage kidney failure.
Will drinking more water increase my GFR?
Staying well hydrated supports overall kidney health and helps maintain kidney function. However, simply drinking more water does not significantly increase GFR in the short term. In some cases, people with kidney disease may even need to restrict fluid intake, so it is important to follow your doctor's advice regarding water consumption.
How do you know if your kidneys are struggling?
Many people are unaware that their kidneys are not functioning properly because early-stage kidney disease usually causes few or no symptoms. This is why annual wellness checkups are important, especially for individuals with diabetes or high blood pressure, as these conditions can increase the risk of CKD.
What colour is urine when your kidneys are failing?
Urine colour may remain normal even when kidney function declines. However, urine may appear foamy or frothy, which can indicate excess protein in the urine. This suggests the kidneys are no longer filtering waste and proteins effectively.
