Blood Urea Nitrogen Test
525 Kshs | Home Collection Available
Synonyms
blood urea nitrogen, BUN, urea nitrogen
Purpose
The Blood Urea Nitrogen (BUN) Test measures the amount of urea nitrogen in the blood, a waste product formed in the liver when the body breaks down protein. The kidneys normally filter urea out of the blood and excrete it in urine.
This test is important for evaluating kidney function. It helps detect renal impairment, dehydration, and liver function issues. Abnormal BUN levels may also reflect problems with protein metabolism or hydration status.
The test can be performed alongside Serum Creatinine, Estimated Glomerular Filtration Rate (eGFR), Electrolyte Panel, Liver Function Tests, and Urinalysis. These combined tests provide a clearer picture of renal and overall metabolic health.
Patient Preparation
No special preparation is required.
Samples
1ml with a minimum volume of 0.7ml of Serum or plasma collected in a Gel-barrier, red-top, or green-top tube (lithium heparin). Avoid using EDTA, oxalate, or citrate plasma. Separate the serum or plasma within 45 minutes of sample collection, and avoid hemolysis. Store the sample at room temperature.
Reference Range
5-20mg/Dl
Results Turnaround
Within one day of receipt of samples.
Diseases / Diagnostic indicators
The BUN test helps assess how well the kidneys and liver are functioning by measuring urea levels in the blood. Urea is a waste product formed from protein breakdown in the liver and excreted by the kidneys.
Some possible outcomes of the test include;
High BUN levels may indicate:
- Chronic kidney diseases like glomerulonephritis or pyelonephritis
- Dehydration
- High protein intake
- Heart failure
- Urinary tract obstruction
Low BUN levels may suggest:
- Liver dysfunction
- Low protein diet
- Malnutrition
- Overhydration
- Pregnancy (due to increased plasma volume and altered protein metabolism)
BUN results are typically interpreted together with creatinine levels for a more accurate evaluation of renal function. For more on Blood Urea Nitrogen Testing, read this study.