What is azotemia (elevated blood urea nitrogen and creatinine levels, indicating impaired renal function)?

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From the Guidelines

Azotemia is a medical condition characterized by abnormally high levels of nitrogen-containing compounds, particularly urea and creatinine, in the blood, which can be caused by various factors including dehydration, heart failure, kidney disease, urinary tract obstruction, and certain medications, and can progress to uremia if left untreated 1.

Definition and Classification

Azotemia occurs when the kidneys are unable to effectively filter waste products from the bloodstream, and can be classified into three types: prerenal (caused by decreased blood flow to the kidneys), renal (resulting from direct kidney damage), and postrenal (due to obstruction of urine outflow) 1.

Causes and Risk Factors

Common causes of azotemia include:

  • Dehydration
  • Heart failure
  • Kidney disease
  • Urinary tract obstruction
  • Certain medications Patients with preexisting renal disease are at increased risk of developing azotemia, and it is commonly associated with cardiac disease, increasing the risk of cardiovascular events 1.

Symptoms and Diagnosis

Symptoms of azotemia may not be present in mild cases, but as it progresses, patients may experience:

  • Fatigue
  • Decreased urination
  • Swelling
  • Nausea
  • Confusion Diagnosis involves blood tests measuring blood urea nitrogen (BUN) and creatinine levels 1.

Treatment and Management

Treatment depends on the underlying cause and may include:

  • Fluid replacement
  • Medication adjustments
  • Treating infections
  • Relieving urinary obstructions Regular monitoring of renal function is crucial to prevent progression to kidney failure, and earlier detection of azotemia allows for earlier intervention and increased chance of prevention or amelioration 1.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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