<prompt> Uremia occurs when total GFR is reduced by ?25506080  <response>: Ans. is a i.e., 25First read about two impoant and interrelated terms :-Azotemia -- Elevation of blood urea nitrogen BUN and creatinine levels without clinical signs and symptoms. Uremia -- Elevation of BUN and creatinine levels with clinical signs and symptoms, i.e. uremia Azotemia Clinical signs and symptoms.Coming back to the question.The evolution from Normal renal function to symptomatic chronic renal failure progresses through four stages ?Diminished renal reserveo The GFR is about 50 of normalo BUN and creatinine values are normal and the patient is asymptomatic.o However, they are more susceptible to developing azotemia with an additional renal insult.Renal insufficiencyo The GFR is 20 to 50 of normal.o Azotemia appears, usually associated with anemia and hypeension.o Sudden stress may precipitate uremia.Renal failureo The GFR is less than 20 to 25 of normal.o The kidney cannot regulate volume and solute composition, and patients develop ove uremia.End-stage renal diseaseo The GRF is less than 5.o This is the terminal stage of uremia. 