Lever
Lifestyle
- Maintain proper hydration
- Regular exercise
- Monitor protein intake
Blutwerte · Marker
Harnstoff
BUN · Blood Urea Nitrogen · Urea · Harnstoff-N
Nierenwerte
- Einheit:
- mmol/L
- Abbreviation
- BUN / Urea
Blood urea nitrogen (BUN) quantifies the amount of nitrogen in the blood that comes from urea, a waste product of protein metabolism.
Reference Ranges
Reference
2.5–7.5mmol/L
2.5
7.5
LowNormalHigh
Reference
Unit · mmol/LReference ranges may vary slightly by laboratory and are influenced by age, sex, and hydration status.
Overview
Übersicht
Urea, also known as blood urea nitrogen (BUN), is a waste product formed in the liver through the urea cycle. It is a major nitrogenous end product of protein metabolism and is excreted by the kidneys through urine. Researchers have found that urea levels in the blood can provide valuable insights into renal function, as the kidneys are responsible for filtering and excreting urea. Elevated or reduced levels of BUN can indicate various health conditions, including kidney dysfunction, dehydration, or liver disease. Clinically, BUN is an essential marker for assessing renal function, often used in conjunction with creatinine levels to provide a more comprehensive view of kidney health. Elevated BUN levels can suggest impaired kidney function or dehydration, while low levels may indicate liver disease or malnutrition. In the context of athletic performance and biohacking, BUN levels can reflect protein metabolism and hydration status. Athletes may monitor BUN to optimize recovery and performance, as dehydration or excessive protein intake can alter BUN levels. However, researchers have observed that BUN levels can be influenced by various factors, including diet, hydration status, and certain medications. It is important to consider these confounders when interpreting BUN results. Fasting is not required for BUN testing, but consistent testing conditions are recommended for accurate monitoring.
Klinische Bedeutung
Elevated BUN levels may indicate kidney dysfunction, dehydration, or high protein intake, while reduced levels can suggest liver disease or malnutrition. BUN is frequently used to assess renal function alongside creatinine.
Dynamics
Trend Interpretation
Rising Values
Progressively rising BUN levels may suggest worsening kidney function or dehydration. Re-test in 4 weeks if values are outside the optimal range.
Falling Values
Progressively falling BUN levels may indicate improved kidney function or overhydration.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Kidney dysfunction
- Dehydration
- High protein intake
- Heart failure
- Gastrointestinal bleeding
Cause
Low Levels
- Liver disease
- Malnutrition
- Overhydration
- Pregnancy
- Low protein diet
Protocol
How to Optimize
Lever
Nutrition
- Balanced diet with adequate protein
- Increase water consumption
- Limit alcohol intake
Note:
Consult a healthcare provider for personalized advice, especially if underlying health conditions are present.
Testing Guidelines
✓Fasting Not Required
✓Not Time-Sensitive
BUN levels can vary throughout the day; morning samples are preferred for consistency.
Testing Frequency
Annually for healthy adults, more frequently if monitoring kidney function.
Interfering Factors
- High protein diet
- Dehydration
- Certain medications
Related Peptides & Hormones
Creatinine
hormone or peptideCorrelated with
Open Research Questions
Current research suggests that the relationship between blood urea nitrogen (BUN) levels and various clinical outcomes, such as diabetes progression and diagnostic delays in celiac disease, remains debated, particularly regarding optimal reference ranges and confounding factors like hydration status. Researchers have not yet established the precise mechanisms by which BUN influences these conditions or the thresholds for clinical significance. Unanswered clinical questions include the role of BUN in predicting acute kidney injury in diverse patient populations.
26 Research Publications
267
Total Citations
15
Human/RCT
2.1
Avg. Influence
2026
Latest
Sort
Filter
01Top
#01
Association of vancomycin plus piperacillin-tazobactam with early changes in creatinine versus cystatin C in critically ill adults: a prospective cohort study.
HumanInfluence3.0
78
This study investigated the effects of vancomycin combined with piperacillin-tazobactam on kidney function in critically ill adults. Researchers found that this combination was associated with increased creatinine levels but did not significantly affect blood urea nitrogen (BUN) or clinical outcomes, suggesting a potential pseudotoxicity.
02Top
#02
Blood urea nitrogen and creatinine.
ReviewInfluence5.0
66
This study highlighted the importance of measuring serum creatinine and blood urea nitrogen (BUN) levels to assess kidney function. Researchers found that these tests are essential, low-cost, and widely available, providing valuable insights into renal health.
03Top
#03
Renal changes and acute kidney injury in covid-19: a systematic review.
Review
34
Researchers conducted a systematic review on renal changes in COVID-19 patients. The review found that increased blood urea nitrogen (BUN) levels were common in patients with acute kidney injury (AKI), indicating significant renal impact from the virus.
04
#04
Blood Urea Nitrogen/Albumin Ratio and Mortality Risk in Patients with COVID-19.
HumanInfluence1.0
19
This study assessed the predictive value of blood urea nitrogen (BUN) and albumin in relation to in-hospital mortality in COVID-19 patients. Researchers found that both BUN and the blood urea nitrogen/albumin ratio (BAR) were significant predictors of mortality, with albumin showing the strongest association.
05
#05
Blood Urea Nitrogen as a Prognostic Marker in Severe Acute Pancreatitis.
HumanInfluence2.0
17
This study evaluated blood urea nitrogen (BUN) as a prognostic marker in patients with severe acute pancreatitis. Researchers found that higher BUN levels were associated with increased mortality and severity of the condition, indicating its potential as a predictive biomarker.
06
#06
A Review of Routine Laboratory Biomarkers for the Detection of Severe COVID-19 Disease.
ReviewInfluence2.0
17
Researchers reviewed laboratory biomarkers for predicting severe COVID-19 disease. They highlighted that blood urea nitrogen (BUN) levels are important indicators of kidney function and disease severity in COVID-19 patients.
07
#07
Blood urea nitrogen and clinical prognosis in patients with COVID-19: A retrospective study.
HumanInfluence1.0
7
This study investigated the relationship between blood urea nitrogen (BUN) levels and clinical outcomes in COVID-19 patients. Researchers found that elevated BUN was a significant risk factor for 28-day mortality, suggesting its utility in clinical prognosis.
08
#08
Potential Biomarkers of Post-stroke Cognitive Impairment in Chinese Population: a Systematic Review and Meta-Analysis.
Meta-Analysis
7
Researchers conducted a meta-analysis to explore the relationship between blood biomarkers and post-stroke cognitive impairment (PSCI). They found no significant differences in blood urea nitrogen (BUN) levels between PSCI and non-dementia groups, suggesting limited diagnostic value.
09
#09
Clinical significance of non-thyroidal illness syndrome on disease activity and dyslipidemia in patients with SLE.
HumanInfluence1.0
7
This study explored the impact of non-thyroidal illness syndrome on disease activity in systemic lupus erythematosus (SLE) patients. Researchers found that blood urea nitrogen (BUN) levels were negatively correlated with disease activity, suggesting its potential as a monitoring tool.
10
#10
Association Between Blood Urea Nitrogen/Albumin and the Incidence as Well as Progression of Type 2 Diabetes.
Liang Yongqi, et al. · Nutrients · 2024
Human
4
This study explored the association between blood urea nitrogen/albumin ratio (BAR) and the risk of developing type 2 diabetes mellitus (T2DM). Researchers found that higher BAR was linked to an increased risk of T2DM and its complications, although its predictive performance was inferior to hemoglobin A1c.
Key findings
- 01Higher blood urea nitrogen/albumin levels were associated with a 5% increased risk of developing type 2 diabetes.
- 02Participants with elevated levels were also more likely to experience serious complications related to diabetes, such as cardiovascular and kidney issues.
- 03Despite these associations, blood urea nitrogen/albumin was not as effective as other markers in predicting diabetes progression.
Publication Trend
Research publications about Harnstoff over time
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