Chronic kidney disease
The extent of kidney dysfunction is categorized into several stages based on GFR: stage 1 with GFR > 90 mL/min per 1.73 m2, stage 2 with GFR 60-89 mL/min per 1.73 m2, stage 3 with GFR 30-59 mL/min per 1.73 m2, stage 4 with GFR 15-29 mL/min per 1.73 m2, and stage 5 with GFR < 15 mL/min per 1.73 m2.
Progressive renal dysfunction results in the accumulation of unfiltered wastes and fluids in the body and is characterized by edema, hematuria, pruritus, fatigue, nausea, and sleep disturbance. Early stages may be asymptomatic or present with few symptoms. With progression of renal dysfunction, several nonspecific symptoms may develop including ecchymosis, vomiting, anorexia, hyposmia, foot and leg edema, pallor, altered taste, and seizures. Urea crystals (uremic frost) may appear on the skin. An infant or child may present with poor growth, polyuria, anemia, hypertension, and uremia (weakness, fatigue, vomiting, and anorexia).
Causes are myriad and include diabetes, hypertension, hyperlipidemia, cardiovascular disease, glomerulonephritis, prior kidney disease, and a history of childhood kidney disease. Diabetes is the most common cause of chronic kidney disease and is responsible for 40% of new cases. Chronic kidney disease can occur in up to 45% of HIV cases, both from infection and complications of treatment, or from comorbid diseases. Agricultural communities, where people are exposed to heat and dehydration and may be exposed to increased nitrate levels in well water, are at increased risk.
Incidence and prevalence vary from nation to nation due to differences in underlying disease rates. In the United States, the incidence of chronic kidney disease is close to 400 per million. Dialysis is the primary means of management once patients progress to renal failure; dialysis patients have an average survival of 3-5 years and prevalence of 1800 cases per million.
Related topic: acute kidney injury
N18.9 – Chronic kidney disease, unspecified
90688005 – Chronic renal failure syndrome
Etiologies of chronic kidney disease can be classified as prerenal, intrinsic renal, and postrenal.
Prerenal conditions include all those in which kidney perfusion is impaired chronically:
- Vascular diseases – Nephrosclerosis, renal artery stenosis
- Glomerular disease – Nephritic conditions (red blood cell casts), nephrotic conditions (proteinuria > 3.5 g/24 h)
- Tubular and interstitial disease – Polycystic kidney disease, Sjögren syndrome, vesicoureteral reflux disease, sarcoidosis