Blood urea nitrogen (BUN)

Definition

Blood urea nitrogen (BUN) is a measure of the amount of nitrogen in the blood that comes from the waste product urea. Urea is produced when protein is metabolized and is typically excreted by the kidneys.

5 Must Know Facts For Your Next Test

1. Elevated BUN levels can indicate impaired kidney function or dehydration.
2. BUN levels can be influenced by dietary protein intake, liver function, and hydration status.
3. Normal BUN range for adults is typically between 7-20 mg/dL.
4. BUN tests are often used alongside creatinine tests to assess renal function.
5. High-protein diets can temporarily raise BUN levels without indicating renal impairment.

Review Questions

• What does an elevated BUN level typically indicate?
• How can dietary protein intake affect BUN levels?
• Why are BUN tests often used in conjunction with creatinine tests?

Related terms

Creatinine:

A waste product from muscle metabolism that is also used to assess kidney function.

Glomerular Filtration Rate (GFR): A test that measures how well your kidneys filter blood.

Uremia:

A condition involving abnormally high levels of waste products in the blood due to poor kidney function.