Definition
Chronic renal failure (CRF) or chronic kidney disease (CKD) is a progressive, irreversible loss of kidney function over months to years, resulting in decreased glomerular filtration rate (GFR) and accumulation of metabolic waste, fluid/ electrolyte imbalances, and systemic complications.
CKD is diagnosed when GFR <60 mL/min/1.73m² for ≥3 months or there are markers of kidney damage (proteinuria, hematuria, imaging changes).
Pathogenesis
- Initial kidney injury (e.g., from diabetes, hypertension) damages nephrons.
- Loss of functioning nephrons → compensatory hyperfiltration in remaining nephrons.
- Intraglomerular hypertension → glomerular sclerosis and further nephron loss.
- Progressive decline in GFR, leading to:
- Retention of nitrogenous waste ( azotemia, uremia ).
- Electrolyte imbalances (e.g., hyperkalemia, hypocalcemia ).
- Acid–base disturbances (metabolic acidosis).
- Fluid overload → hypertension and edema.
- Decreased erythropoietin → anemia.
Clinical Manifestations
General / Constitutional
Fatigue, weakness.
Anorexia, nausea, weight loss.
Uremic fetor (urine-like breath odor ).
Cardiovascular
Hypertension.
Pericarditis, arrhythmias.
Increased risk of heart failure.
Hematologic
Normocytic normochromic anemia (↓ erythropoietin).
Platelet dysfunction → bleeding tendency.
Electrolyte & Acid–Base
Hyperkalemia, hypocalcemia, hyperphosphatemia.
Metabolic acidosis.
Skeletal
Renal osteodystrophy due to secondary hyperparathyroidism.
Neurologic
Confusion, sleep disturbances.
Peripheral neuropathy ("restless legs").
Skin
Pruritus.
Pallor, ecchymoses.
Gastrointestinal
Nausea, vomiting, uremic gastritis.