Urea
Blood urea nitrogen (BUN)
The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain between 6 to 20 mg of urea nitrogen per 100 ml. Individual laboratories may have different reference ranges,
and this is because the procedure may vary.
Interpretation
BUN is an indication of renal health. Normal ranges 8-20 mmol/L. If Glomerular Filtration Rate (GFR) and blood volume decrease (hypovolemia) then BUN will increase. Other factors responsible for its increment are fever, increased catabolism, high protein diet and gastrointestinal bleeding.