US Medical Term · tests
Blood Urea Nitrogen (BUN)
Nitrógeno ureico en sangre
Also: BUN (regional variant)
In 9 languages
| Language | Term |
|---|---|
| English | Blood Urea Nitrogen (BUN) |
| Spanish (Español) | Nitrógeno ureico en sangre |
| Chinese (中文) | 血液尿素氮 |
| Korean (한국어) | 혈액 요소 질소 |
| Vietnamese (Tiếng Việt) | Xét nghiệm ure nitơ máu |
| Filipino (Tagalog) | Blood Urea Nitrogen |
| Portuguese (Português) | Ureia sérica (BUN) |
| Thai (ภาษาไทย) | การตรวจไนโตรเจนยูเรียในเลือด |
| Japanese (日本語) | 血中尿素窒素 |
What it means
The blood urea nitrogen (BUN) test measures the amount of urea nitrogen in your blood. Urea is a waste product formed when your liver breaks down protein from food. Healthy kidneys filter urea out of the blood into urine. A high BUN level can signal that your kidneys are not filtering properly, or that you are dehydrated or eating a very high-protein diet. Blood is drawn from a vein in your arm. BUN is almost always interpreted together with creatinine; the BUN-to-creatinine ratio helps doctors distinguish between kidney problems and dehydration. Normal adult BUN is roughly 7–20 mg/dL.
How to say it
Sentences a patient might use with a doctor, nurse, pharmacist, or insurer:
What is a BUN test and why is my doctor checking my urea nitrogen?
¿Qué es la prueba de BUN y por qué mi médico revisa el nitrógeno ureico?
My BUN is high — could that just be from eating too much protein?
Mi BUN está alto — ¿podría ser solo por comer demasiada proteína?
Is the BUN test done with a blood draw or a urine sample?
¿La prueba de BUN se hace con sangre o con una muestra de orina?
Where you'll see it
Related terms
Sources
Last reviewed: September 2026