BUN · low result
What does a low BUN mean?
Short answer
A low BUN is usually unremarkable — a low-protein or vegetarian diet, overhydration, pregnancy, or a small body — but it can accompany liver disease, because the liver makes urea, and severe malnutrition. On its own it rarely needs follow-up.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
What is the normal range for BUN?
- age 18+: 7.00 – 20.0 mg/dL
Can reflect low-protein intake, liver disease, or overhydration.
Full reference table, citations and testing options: BUN biomarker page.
What are the common causes of low BUN?
- Low-protein diet, malnutrition
- Overhydration
- Pregnancy
- Liver disease (reduced urea production)
What symptoms go with low BUN?
- None from the BUN itself
What do clinicians usually check next?
- Liver panel if unexplained
- Nutrition review
How do you recheck BUN?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Basic Metabolic Panel | Test · 8 biomarkers | $20.99 | Yes | 1–3 business days |
Common questions
Should I worry about a low BUN?
Usually not. It reflects diet or hydration far more often than disease.
Sources
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.