chronic renal failure is defined as progressive and irreversible loss of renal function. The most common causes ultimately leading to end-stage renal disease(ESRD) are listed.

Loss of 75% of glomerular filtration rate(GFR) does not usually result in pronounced symptoms because the remaining glomeruli hyperfiltration, and the tubules adjust by maintaining adequate acid-base, fluid and electrolyte balance. For example, the doubling of serum creatinine from 0.7 to 1.4 mg/dL signifies a loss of approximately 50% of the GFR and emphasizes the importance of early recognition and intervention at this stage.

Serum creatinine, creatinine clearance, and the reciprocal of the serum creatinine plotted against time are commonly used for diagnosing and monitoring renal dysfunction. These are in their accuracy and may be affected by drugs or other illnesses, but are the only practical and cost-effective means of monitoring patients with chronic renal insufficiency. When patients have an elevated serum creatinine acute renal failure must be differentiated from chronic renal failure, as discussed in Chapter 30. Every attempt should be made to arrive at the specific cause of chronic renal failure. One of the most important pieces of data is prior laboratory measurements of the serum creatinine concertration. Renal biopsy is the most specific tool to reach a definitive diagnosis. This allows treatment of the underlying cause, assessment of the prognosis, and determination of suitability for kidney transplantation. If the biopsy is not performed because of small kidney size,on present, diagnosis is a made based on present. past and family history, serologic evaluation, examination of the urine sediment, and ultrasound evaluation.

Although most chronic kidney diseases are associated with a progressive decrease in kidney size, a few systemic diseases are characterized by normal kidney size despite advanced renal failure.

These diseases include diabetes mellitus, multiple myeloma, polycystic kidney disease, nephropathy related to acquired immunodeficiency syndrome, and amyloidosis.