Modified Berthelot Method 

Quantitative determination of Urea on serum, plasma and urine according to Berthelot modified reaction.

Urea derives from protein catabolism, more than 90% is excreted through the kidneys. The increase in plasma urea can occur from kidney or heart failure, loss of water and salts, obstruction of the urinary tract, or increased protein breakdown. A decrease can be found in cases of hyperhydration, severe hepatic insufficiency, increased protein synthesis, deficient protein intake in the diet.