II. Pathophysiology

  1. Increases by 10-20 mg/dl/day if Renal Function absent
  2. Serum Creatinine is a better measure of Renal Function
    1. BUN is Protein dependent
      1. High protein diet
      2. Catabolism
    2. BUN is reabsorbed at renal tubules
      1. Prerenal Failure
        1. Dehydration
        2. Congestive Heart Failure
      2. Postrenal Failure
        1. Obstructive Uropathy

IV. Decreased BUN

  1. Liver disease
  2. Poor nutrition
  3. Overhydration
  4. Third trimester of pregnancy

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Ontology: Blood urea nitrogen measurement (C0005845)

Definition (NCI_CDISC) A measurement of the urea nitrogen in a blood specimen.
Definition (NCI) A quantitative measurement of the amount of urea nitrogen present in a serum sample.
Definition (MSH) The urea concentration of the blood stated in terms of nitrogen content. Serum (plasma) urea nitrogen is approximately 12% higher than blood urea nitrogen concentration because of the greater protein content of red blood cells. Increases in blood or serum urea nitrogen are referred to as azotemia and may have prerenal, renal, or postrenal causes. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Concepts Laboratory Procedure (T059)
MSH D001806
SnomedCT 144012007, 166710001, 166722003, 144004004, 105011006, 250623007, 24509005
CPT 84520, 80069, 80048, 80047
English Blood Urea Nitrogen, BUN, Nitrogen, Blood Urea, Urea Nitrogen, Blood, Blood urea nitrogen measurement, blood urea nitrogen, Blood urea nitrogen, Urea nitrogen; quantitative, Urea - blood, Blood Urea Nitrogen Measurement, urea blood, blood urea, blood urea nitrogen (BUN) level test, bun measurement, Measurement of blood urea nitrogen (BUN), ASSAY OF UREA NITROGEN QUANTITATIVE, Measurement of urea nitrogen (BUN), Blood urea (procedure), BUN measurement, Blood urea, Blood urea measurement (procedure), Blood urea measurement, Blood urea nitrogen measurement (procedure), ASSAY OF UREA NITROGEN, Assay of urea nitrogen
Italian Urea nel sangue, Azoto ureico, Azoto ureico ematico, BUN, Azotemia
Dutch bloed ureum stikstof, bloed ureum, BUN, Blood-urea nitrogen
French Azote uréique du sang, BUN, Azote uréique sérique, Azote uréique sanguin, Urée sanguine
German BUN, Harnstoff-Stickstoff im Blut, Blutharnstoff, Reststickstoff im Serum
Portuguese Azoto ureico no sangue, Nitrogênio da Ureia Sanguínea, BUN, Ureia Plasmática, Ureia no sangue, NUS
Spanish Nitrógeno ureico en sangre, BUN, determinación de uremia, medición de BUN, medición de NUS, medición de nitrógeno ureico en sangre (procedimiento), medición de nitrógeno ureico en sangre, medición de uremia (procedimiento), medición de uremia, Urea en sangre, NUS, Nitrógeno de la Urea Sanguínea
Japanese BUN, 血中尿素, ケッチュウニョウソチッソ, ケッチュウニョウソ, BUN, 血清尿素窒素, 血中尿素窒素, 血液尿素窒素
Swedish Blodurea
Finnish Ureatyppi
Czech Močovina v krvi, Dusík močoviny v krvi, dusík močoviny v krvi, hladina dusíku močoviny v krvi, krev - dusík močoviny, močovinový dusík v krvi
Polish Azot mocznika krwi
Hungarian Karbamid-nitrogén vérszint, BUN, Karbamid vérszint
Norwegian BUN, Blodureanitrogen, Ureanitrogen i blodet