Stages of Chronic Kidney Disease (CKD): A Comprehensive Guide

Introduction

Chronic kidney disease (CKD) is a progressive condition characterised by the gradual loss of kidney function over time. This disease can go unnoticed for a long time as the symptoms often don’t surface until the kidneys are significantly impaired. Classified into five distinct stages based on the estimated glomerular filtration rate (eGFR), CKD’s progression can be monitored effectively. The eGFR measures how well the kidneys filter waste from the blood, giving us valuable insight into our kidney health. Let’s look at the stages of CKD to see how it affects kidney function over time.

Stages of CKD

In the journey of understanding chronic kidney disease, it’s essential to comprehend its stages. Each stage represents the severity of the condition and has specific symptoms and medical advice associated with it.

Here are the 5 stages of CKD that show how kidney function declines.

CKD Stage 1

In the first stage of CKD, there is mild kidney damage. However, despite this damage, the kidneys are still functioning normally. There may be signs of kidney damage like protein in the urine, but patients often do not experience any noticeable symptoms.

Stage of CKD	eGFR Result	Meaning
Stage 1	90 or higher	Mild kidney damage

However, some signs you might observe in CKD Stage 1 include:

• High blood pressure
• Swelling in the hands or feet
• Repeated urinary tract infections
• Protein in urine (proteinuria)
• Blood in urine (haematuria)
• Imaging findings indicating kidney damage, detectable through ultrasound, CT scans, MRI, or kidney biopsy.

While the damage at this stage may not be reversible, proactive management can help maintain kidney function and slow disease progression.

Regular monitoring and lifestyle changes are crucial for patients diagnosed with stage 1 CKD. A healthy diet, controlling blood pressure, and managing blood sugar levels can go a long way in preserving kidney health and slowing down the progression of the disease.

CKD Stage 2

In the stages of Chronic Kidney Disease (CKD), stage 2 marks the beginning of mild kidney damage. This stage indicates that kidney damage has been ongoing for at least three months. This stage signifies the presence of kidney damage for at least three months, which may be shown through various conditions such as albuminuria (protein in urine), haematuria (blood in urine), or abnormalities identified in imaging tests.

Stage of CKD	eGFR Result	Meaning
Stage 2	60-89	Mild kidney damage

While CKD stage 2 is often asymptomatic, some individuals may start to notice subtle symptoms related to the underlying kidney damage. Possible symptoms include:

• High blood pressure (hypertension)
• Proteinuria
• Urinary tract infections (UTIs)
• Hematuria
• Oedema, which is swelling particularly noticeable in the legs and feet

If any symptoms do occur, they may be subtle and often relate directly to specific kidney damage rather than the kidney disease itself. For instance, individuals may notice foamy urine if they have significant proteinuria.

CKD Stage 3

This stage indicates moderate kidney damage along with a more significant decline in kidney function. At this juncture, patients may start experiencing more noticeable symptoms and complications as kidney function recedes.

Stage of CKD	eGFR Result	Meaning
Stage 3a	45-59	Mild to moderate kidney damage
Stage 3b	30-44	Moderate to severe damage

In stage 3 CKD, symptoms become more obvious and can include:

• Fatigue and weakness
• Swelling in the legs, ankles, or feet due to fluid retention
• Changes in urination patterns such as more frequent urination or diminished urine output
• High blood pressure
• Nausea and vomiting
• Loss of appetite
• Sleep problems
• Dry, itchy skin
• Muscle cramps

As the kidney function continues to deteriorate, patients may also experience complications such as anaemia, bone disease, and cardiovascular disease. Therefore, regular monitoring and management of underlying conditions, like diabetes and hypertension, become increasingly vital at this stage to slow down the progression of CKD.

CKD Stage 4

Stage 4 CKD signals severe and irreversible kidney damage. Your kidneys at this point are functioning at just 15-29% of their normal capacity. Consequently, waste products begin to accumulate in your blood causing various complications.

Stage of CKD	eGFR Result	Meaning
Stage 4	15-29	Severe kidney damage

The symptoms of stage 4 kidney disease can become more noticeable, and may include:

• Feeling tired and weak
• Swelling in the legs, ankles, or feet due to fluid retention
• Changes in urination patterns
• High blood pressure
• Nausea and vomiting
• Loss of appetite
• Sleep problems
• Dry, itchy skin
• Muscle cramps
• Difficulty concentrating
• Nerve problems including numbness or tingling in toes or fingers

Additionally, patients with stage 4 CKD are susceptible to complications including anaemia, bone disease, heart disease, elevated potassium levels, and high phosphorus levels. As such, regular monitoring and management of these complications become crucial at this stage.

CKD Stage 5

Moving towards the final stages of CKD, stage 5 CKD, also named end-stage renal disease (ESRD), is marked by kidney failure. At this terminal phase, the kidneys are operating at only about 10-15% of their normal capacity. Hence, life-sustaining measures such as dialysis or a kidney transplant become necessary.

Stage of CKD	eGFR Result	Meaning
Stage 5	Less than 15	Most severe kidney damage or kidney failure

Symptoms associated with stage 5 kidney disease can be quite severe. In addition to the symptoms observed in stage 4, you may encounter:

• Severe fatigue and weakness
• Persistent nausea and vomiting
• Confusion and difficulty concentrating
• Swelling throughout the body
• Shortness of breath
• Chest pain
• Seizures
• Coma

For patients battling stage 5 CKD, immediate treatment is indispensable to remove waste products from their blood and avert life-threatening complications. The two primary treatment options are dialysis (either haemodialysis or peritoneal dialysis) and kidney transplantation.

Regular consultations with a nephrologist or kidney specialist are key for managing both stage 4 and stage 5 CKD. The focus of treatment pivots on slowing down the progression of the disease, managing complications and preparing for dialysis or transplantation. Adopting a kidney-friendly diet, adhering to prescribed medications, and making crucial lifestyle modifications can help preserve the remaining kidney function and improve overall health.

Also Read: 10 Ways to maintain Your Kidney Health

How to Identify Stage of CKD

To identify the stage of chronic kidney disease (CKD), your doctor will typically rely on a combination of tests and clinical assessments. The primary methods used for CKD stage identification are:

1. Estimated Glomerular Filtration Rate (eGFR): This blood test reveals how effectively your kidneys are eliminating waste from your bloodstream. The eGFR reading is computed based on serum creatinine levels – which vary with age, sex and race.
   • Stage 1 CKD: eGFR ≥ 90 mL/min
   • Stage 2 CKD: eGFR 60-89 mL/min
   • Stage 3 kidney disease: eGFR 30-59 mL/min (Further categorised into 3A and 3B)
   • Stage 4 kidney disease: eGFR 15-29 mL/min
   • Stage 5 kidney disease: eGFR < 15 mL/min or dialysis required
2. Urine Tests: A urinalysis can identify abnormalities such as proteinuria (protein in urine) and haematuria (blood in urine), indicative of kidney damage. Doctors often also assess the albumin-to-creatinine ratio in urine, with significant albuminuria pointing to advanced stages of CKD.
3. Blood Pressure Monitoring: High blood pressure is common in patients with CKD and can be both a cause and a consequence of kidney damage. Regular monitoring helps assess overall kidney health.
4. Imaging Tests: Techniques like ultrasound, CT scans, or MRI can help doctors visualise kidney structure and detect any abnormalities that may suggest kidney damage.
5. Clinical Symptoms: Fatigue, swelling, changes in urination, and other symptoms can start to appear as the disease progresses, especially in stages 4 and 5 of CKD. However, patients in the early stages of CKD may not show any symptoms.

Importance of Comprehensive Assessment

The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend using both eGFR and urine albumin levels together to improve the accuracy of CKD staging and prognosis. This approach helps in identifying patients at risk for progressing to more severe stages of CKD and allows for timely intervention.

In summary, identifying the stage of CKD involves a blend of blood tests, urine tests, imaging studies, and clinical assessments. This comprehensive view of kidney function and health helps doctors devise an effective treatment plan. Regular monitoring and follow-ups are essential for managing CKD and preventing progression.

By understanding these stages, one can better comprehend the seriousness of their condition and take appropriate steps to manage it effectively. Remember, early detection is key to slowing down the progression of Chronic Kidney Disease. So adhere to your doctor’s advice, keep up with your scheduled check-ups and stay proactive about your health.

Frequently Asked Questions (FAQs)

References

1. https://www.nhs.uk/conditions/kidney-disease/#:~:text=Chronic%20kidney%20disease%20(CKD)%20is,or%20of%20south%20Asian%20origin.
2. https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521
3. https://my.clevelandclinic.org/health/diseases/15096-chronic-kidney-disease
4. https://www.ncbi.nlm.nih.gov/books/NBK535404/
5. https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd
6. https://www.kidney.org/atoz/content/about-chronic-kidney-disease
7. https://www.kidneyfund.org/all-about-kidneys/stages-kidney-disease