blood urea level serum urea level 2022-02-25T09:49:54Z CMO:0003877 OBA:2050065 This is the level of urea in blood serum, i.e. blood plasma from which clotting factors have been removed. This value can be determined by converting urea nitrogen to urea concentration by multiplying urea nitrogen concentration by 60/28 or 2.14. Urea is the chief nitrogenous end product of protein metabolism in whole blood. Urea is formed in the liver from amino acids and from ammonia compounds and can be found in urine, blood, and lymph. clinical_measurement_ontology serum urea concentration serum urea measurement slaulede