Hypothyroidism can cause both decreased GFR and hypovolemia, but BUN-to-creatinine ratio has been found to be lowered in hypothyroidism and raised in hyperthyroidism. The main causes of an increase in BUN are: high-protein diet, decrease in glomerular filtration rate (GFR) (suggestive of kidney failure), decrease in blood volume ( hypovolemia), congestive heart failure, gastrointestinal hemorrhage, fever, rapid cell destruction from infections, athletic activity, excessive muscle breakdown, and increased catabolism. The normal range is 2.1–7.1 mmol/ L or 6–20 mg/ dL. Interpretation īUN is an indication of renal (kidney) health. It is not considered as reliable as creatinine or BUN/creatinine ratio blood studies. The test is used to detect renal problems. Individual laboratories will have different reference ranges, as the assay used can vary between laboratories. Normal human adult blood should contain 6 to 20 mg/dL (2.1 to 7.1 mmol/L) of urea nitrogen. The liver produces urea in the urea cycle as a waste product of the digestion of protein. 6299-2, 59570-2, 12961-9, 12963-5, 12962-7īlood urea nitrogen ( BUN) is a medical test that measures the amount of urea nitrogen found in blood.

Normal bun rang