What is a Blood Urea Nitrogen (BUN)Test?

A blood urea nitrogen test or BUN test is performed to evaluate how well the kidneys work. The liver breaks down the protein into smaller components, producing BUN, or blood urea nitrogen. Typically, the kidneys filter out this waste, which is then eliminated from the body through urination. Unhealthy kidneys have trouble removing BUN and leaving more of it in the blood; as a result, the levels of urea and nitrogen keep rising.The blood urea nitrogen test, also called a BUN blood test or serum BUN test, measures how much of the waste product you have in your blood.

When is the Blood urea nitrogen (BUN) test done?

A doctor may recommend Blood Urea Nitrogen blood (BUN)tests

To detect kidney function
To determine the effectiveness of dialysis treatment.

As a routine investigation

While treating diabetes

To rule out GI disorder

Dehydration

Urinary tract obstruction

Congestive heart failure

What are the components of a Blood Urea nitrogen or BUN test?

BUN tests can be done alone or with a creatinine blood test to diagnose kidney disease appropriately.

What is the standard reference range for the Blood Urea nitrogen (BUN)test?

The usual result is generally 6 to 20 mg/dL

Higher value

More than 20 mg/dL may be due to the following reasons

Dehydration
Heart failure.

The kidney is not functioning properly

A high-protein diet
Addison's disease
Tissue damage (such as from severe burns)

Bleeding in the gastrointestinal tract.

Higher BUN-to-creatinine ratios occur with sudden (acute) kidney problems and may indicate shock or severe dehydration

Lower Blood urea nitrogen( BUN) levels can indicate:
Liver failure.
Malnutrition.
Severe lack of protein in the diet.
Overhydration.

How is the Blood urea nitrogen (BUN)test done?

The test requires a blood sample
This test poses no risk to the patient.
Results are usually reported within a few hours after the blood is drawn.

Blood Urea Nitrogen (BUN) Test in Perinthalmanna

Blood Urea Nitrogen (BUN) Test in Perinthalmanna

B0050

Daily

No Special Preparation Required

Same Day

₹150

Parameters

Copyright © 2026 Aster Clinical Lab LLP. All Rights Reserved