Chronic Kidney Disease (CKD): Symptoms, Stages, Causes, Diagnosis, and Management

Chronic Kidney Disease is a clinically important renal topic. Diagnosis is made if either of the following is present for >3 months:

What Is Chronic Kidney Disease?

Chronic Kidney Disease (CKD) is defined as abnormalities of kidney structure or function present for >3 months, with implications for health.

Diagnosis is made if either of the following is present for >3 months:

1. Markers of kidney damage, such as:

• albuminuria / proteinuria
• urine sediment abnormalities
• electrolyte abnormalities due to tubular disorders
• structural abnormalities on imaging
• histological abnormalities
• history of kidney transplantation

1. eGFR <60 mL/min/1.73 m² for >3 months

A patient can have CKD with preserved eGFR if there is persistent albuminuria or structural damage.

Why Chronic Kidney Disease Matters

• Define CKD and diagnose it using duration, eGFR, albuminuria, and structural abnormalities.
• Explain the anatomical and physiological basis of CKD progression.
• Classify CKD using cause, GFR category, and albuminuria category (CGA).
• Recognize common causes and risk factors.

Definition and Diagnostic Criteria

Chronic Kidney Disease (CKD) is defined as abnormalities of kidney structure or function present for >3 months, with implications for health.

Diagnosis is made if either of the following is present for >3 months:

1. Markers of kidney damage, such as:

• albuminuria / proteinuria
• urine sediment abnormalities
• electrolyte abnormalities due to tubular disorders
• structural abnormalities on imaging
• histological abnormalities
• history of kidney transplantation

1. eGFR <60 mL/min/1.73 m² for >3 months

A patient can have CKD with preserved eGFR if there is persistent albuminuria or structural damage.

For a formal framework, see the KDIGO guidance.

Classification and Staging

A. By cause

• diabetic kidney disease
• hypertensive nephrosclerosis
• chronic glomerulonephritis
• chronic pyelonephritis / reflux nephropathy
• tubulointerstitial disease
• polycystic kidney disease
• obstructive nephropathy
• systemic diseases (SLE, vasculitis, amyloidosis, myeloma)

B. By GFR category

C. By albuminuria category

D. Practical classification: CGA

CKD should ideally be described using:

• Cause
• GFR category
• Albuminuria category

Example: Diabetic kidney disease, G3bA3.

Common Causes of Chronic Kidney Disease

Common causes

1. Diabetic kidney disease

• most common cause in many settings
• associated with albuminuria, HTN, retinopathy, progressive eGFR decline

2. Hypertensive nephrosclerosis

• long-standing hypertension
• usually lower-grade proteinuria than primary glomerular disease

3. Chronic glomerular diseases

• IgA nephropathy
• FSGS
• membranous nephropathy
• lupus nephritis
• post-infectious sequelae

4. Chronic tubulointerstitial disease

• analgesic nephropathy
• reflux nephropathy
• chronic pyelonephritis
• hypercalcemic nephropathy
• urate nephropathy

5. Hereditary / cystic disease

• ADPKD
• Alport syndrome

6. Obstructive and urological causes

• prostatic disease
• stones
• strictures
• reflux
• congenital anomalies

7. Systemic diseases

• SLE
• vasculitis
• amyloidosis
• multiple myeloma
• scleroderma

If you want to compare this with acute kidney injury (AKI), you can also browse the Nephrology category.

Chronic Kidney Disease Symptoms and Clinical Features

Early disease

Often asymptomatic and detected by:

• raised creatinine / low eGFR
• albuminuria / proteinuria
• abnormal urinalysis
• small kidneys on imaging

Symptoms in progressive CKD

• fatigue
• anorexia
• nausea
• pruritus
• nocturia
• polyuria early due to concentrating defect
• edema
• breathlessness
• muscle cramps
• poor appetite
• sleep disturbance
• bone pain in advanced CKD-MBD
• neuropathic symptoms in severe uremia

Signs

• hypertension
• pallor
• edema
• scratch marks / pruritus
• signs of fluid overload
• peripheral neuropathy in advanced disease
• uremic fetor / pericardial rub in severe uremia
• features of underlying cause, e.g. diabetic retinopathy, vasculitic rash, enlarged kidneys in ADPKD

Diagnosis and Evaluation of Chronic Kidney Disease: A Practical Approach

Stepwise approach to suspected CKD

1. Confirm chronicity

• abnormal renal function or kidney damage for >3 months
• previous creatinine / eGFR trends
• old urine tests
• prior imaging

1. Differentiate CKD from AKI or AKI on CKD

• compare baseline and recent trend
• look for acute oliguria, rapidly rising creatinine, acute illness

1. Look for markers of damage

• albuminuria / proteinuria
• hematuria
• structural abnormalities

1. Identify cause

• diabetes?
• hypertension?
• glomerular disease?
• obstructive disease?
• hereditary disease?

1. Assess severity and risk

• GFR category
• albuminuria category
• blood pressure
• complications

1. Screen for complications

• anemia
• CKD-MBD
• acidosis
• hyperkalemia
• cardiovascular disease

1. Plan long-term care

• renoprotection
• complication management
• nephrology referral if needed
• RRT education/preparation when advanced

Practical CKD clinic algorithm

“`mermaid

flowchart TD

A[Abnormal creatinine/eGFR or proteinuria] –> B[Confirm chronicity >3 months]

B –> C[Exclude AKI or AKI on CKD]

C –> D[Urinalysis + ACR/PCR + BP + medication review]

D –> E[Ultrasound kidneys]

E –> F[Assign Cause + G category + A category]

F –> G[Check complications: anemia, K, HCO3, Ca, PO4, PTH]

G –> H[Renoprotective treatment]

H –> I[Monitor progression and complications]

I –> J{Advanced disease?}

J –>|Yes| K[RRT planning / transplant evaluation]

J –>|No| L[Continued CKD follow-up]

“`

Basic investigations

• serum creatinine, urea, electrolytes
• eGFR trend
• urine routine examination
• urine ACR or PCR
• CBC
• calcium, phosphate, bicarbonate, albumin
• blood pressure measurement
• blood glucose / HbA1c
• lipid profile

Urine-focused evaluation

• dipstick for blood and protein
• microscopy for RBCs, WBCs, casts
• ACR for albuminuria assessment
• PCR if heavy proteinuria suspected
• culture if infection suspected

Imaging

• Ultrasound kidneys:
• kidney size
• cortical thickness
• echogenicity
• corticomedullary differentiation
• cysts
• hydronephrosis / obstruction

Etiology-specific tests

• ANA, anti-dsDNA, ANCA, complements
• serum electrophoresis / light chains
• hepatitis B/C, HIV if indicated
• HbA1c, fundoscopy in diabetes
• genetic / family evaluation where relevant

Complication assessment

• iron studies, ferritin, transferrin saturation
• B12 / folate when appropriate
• PTH, vitamin D, calcium, phosphate, ALP
• ECG / echocardiography if cardiovascular involvement suspected

When biopsy may be needed

• unexplained CKD
• disproportionate proteinuria
• active urinary sediment
• suspected treatable glomerular disease
• atypical diabetic kidney disease

For a patient-friendly overview, see the NIDDK page.

Interpretation Frameworks

1. eGFR trend interpretation

• a single low eGFR does not define CKD unless persistent >3 months
• progression is assessed by serial values
• rapid decline suggests superimposed AKI, active disease, obstruction, or aggressive glomerular pathology

2. Albuminuria / proteinuria interpretation

Albuminuria predicts:

• CKD progression
• cardiovascular events
• mortality

3. Urinalysis interpretation in CKD

4. AKI vs CKD clues

5. Electrolyte and acid-base interpretation

CKD commonly causes:

• hyperkalemia
• metabolic acidosis
• hyperphosphatemia
• hypocalcemia tendency
• secondary hyperparathyroidism

6. Cardiovascular risk interpretation

CKD is a major cardiovascular risk state even before kidney failure. A mild-moderate CKD patient may die from CV disease before reaching dialysis.

Differential Diagnosis

• AKI
• AKI on CKD
• transient pre-renal azotemia
• obstructive uropathy
• isolated albuminuria without CKD (must assess persistence and structure)
• pseudo-low eGFR in unusual body composition states

Management of Chronic Kidney Disease

Core goals

• slow CKD progression
• reduce cardiovascular risk
• treat complications
• prepare for RRT if needed
• preserve quality of life

1. Treat the cause

• optimize diabetes control
• control blood pressure
• treat glomerular disease where appropriate
• relieve obstruction
• stop nephrotoxins
• treat recurrent infection / reflux if relevant

2. Renoprotective strategy

Blood pressure control

• central pillar of CKD care
• target individualized according to albuminuria, diabetes, age, frailty, and guideline framework
• ACEi/ARB especially useful in albuminuric CKD unless contraindicated

RAAS blockade

• ACEi / ARB reduces intraglomerular pressure and proteinuria
• monitor after initiation or dose increase:
• creatinine
• potassium
• acceptable small creatinine rise may occur; large rise requires review for renovascular disease, dehydration, NSAID use, or overdiuresis

SGLT2 inhibitors

• important renoprotective drugs in diabetic and selected non-diabetic CKD
• reduce progression and CV events
• watch volume status and acute illness rules

Lifestyle measures

• salt restriction
• smoking cessation
• weight control
• regular exercise
• avoid nephrotoxins

3. Management of complications

Edema / fluid overload

• salt restriction
• loop diuretics
• monitor weight and volume status

Hyperkalemia

• dietary potassium review
• review ACEi/ARB/MRA and other contributors
• correct acidosis
• potassium binders in selected patients
• urgent treatment if severe

Metabolic acidosis

• oral bicarbonate when indicated
• treat contributing factors

CKD-MBD

• dietary phosphate restriction when appropriate
• phosphate binders
• vitamin D / active vitamin D analogues in selected patients
• manage secondary hyperparathyroidism

Anemia of CKD

• evaluate iron, B12, folate, blood loss
• iron replacement if deficient
• ESA therapy in selected patients after appropriate evaluation

Cardiovascular protection

• statins in many CKD patients not yet on dialysis
• antiplatelet therapy when indicated for CV disease, not just because CKD exists

4. Nutrition and counseling

• dietitian involvement when possible
• salt moderation
• protein intake individualized
• potassium and phosphate advice based on labs
• vaccination and sick-day education

5. Advanced CKD care

• discuss prognosis and trajectory
• prepare vascular access or peritoneal dialysis planning where appropriate
• transplant evaluation if suitable
• conservative kidney management discussion in frail or non-dialysis candidates

6. Monitoring

Monitor according to stage/risk:

• creatinine / eGFR trend
• urine ACR / PCR
• potassium and bicarbonate
• calcium, phosphate, PTH
• hemoglobin and iron studies
• BP and volume status
• medication safety

Complications of Chronic Kidney Disease

• hypertension
• edema / fluid overload
• hyperkalemia
• metabolic acidosis
• anemia
• CKD-MBD / secondary hyperparathyroidism
• malnutrition
• cardiovascular disease
• neuropathy
• uremic symptoms
• progression to kidney failure

FCPS/MRCP Exam Pearls and Clinical Boxes

Frequently Asked Questions About Chronic Kidney Disease

Can chronic kidney disease improve or be stabilized?

That depends on the cause and the stage of disease. Early recognition, risk-factor control, and prompt treatment of complications often improve outcomes and may slow progression substantially.

When should chronic kidney disease become urgent?

Urgent escalation is needed when severe complications, rapid deterioration, marked biochemical abnormalities, or major cardiorespiratory compromise appear.

Conclusion

CKD is a chronic, systemic, progressive disorder of nephron loss and renal dysfunction. The exam approach is to confirm chronicity, classify by CGA, identify the cause, quantify albuminuria, detect complications, slow progression, reduce cardiovascular risk, and prepare early for renal replacement therapy when advanced disease approaches. A structured bedside approach, early recognition of complications, and appropriate nephrology follow-up remain central to safe care.

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Medical disclaimer: This article is for medical education and professional awareness. Clinical decisions should always be individualized according to the patient’s condition, local protocols, and specialist advice when necessary.