Chronic renal failure (CRF) is a progressive disease characterized by an increasing inability of the kidney to maintain normal low levels of the products of

Renal function is clinically monitored by measurement of 

Once serum creatinine in an adult reaches about 3 mg/dL 

In patients with an elevated serum creatinine level (1.5 to 3.0 mg/dL), the term chronic renal insufficiency is useful and implies that progression to CRF and ESRD is not inevitable. 

Azotemia means an elevation of BUN above normal,

Uremia implies the presence of symptoms secondary to renal nitrogen retention

Renal replacement therapy (RRT). 


Pathophysiology of chronic renal failure

Pathophysiology and Clinical manifestations of Uremic syndrome 

Patients are often not seen until late in the course of the disease, when much of their kidney function has already been lost  Kidney adapts so well to progressive loss of nephrons and can maintain constancy of the internal environment until about 75% of renal function has been lost. Patients with uremic manifestations, can have a myriad of different complaints referable to almost any organ system.

Differential diagnosis

It is sometimes difficult to differentiate between acute and chronic renal failure when a patient with azotemia and an elevated serum creatinine concentration is recognized for the first time. 

A diagnosis of CRF is supported by a 

Acute-on-chronic renal failure is a common circumstance, and reversible factors should always be sought when a diagnosis of CRF is made or when a patient with CRF shows unexpectedly rapid deterioration in renal function. 

Potentially reversible factors in chronic renal failure

Specific diagnosis




Laboratory studies should include measurement of serum electrolytes, calcium, phosphorus, alkaline phosphatase, and albumin. 


Patients with systemic disease (diabetes mellitus, hypertension, Wegener's granulomatosis, and systemic lupus erythematosus) potentially involving the kidney must be regularly checked