Clinical Chemistry - Urea

Urea is synthesized in the liver from ammonia, as a result of deamination of amino acids. This biosynthetic pathway is the chief means of excretion of surplus nitrogen by the body. Measurements obtained by this test are used in the diagnosis of renal and metabolic disorders, most frequently kidney disorders. More than 60% of the kidney must be destroyed before plasma urea levels are significantly raised. This test is most frequently used in conjunction with serum creatinine for increased protein levels (cardiac decompensation, water depletion).