Back to all articles

  1. Home
  2. News
  3. Health Queries Answered
  4. Understanding Blood Tests for Kidney Function

Understanding Blood Tests for Kidney Function


Key blood tests for kidney function include serum creatinine, blood urea nitrogen (BUN), and estimated glomerular filtration rate (eGFR), which help diagnose and monitor kidney diseases.

Blood tests are essential for assessing kidney function and diagnosing kidney diseases. Here’s a detailed explanation of the key tests, what they measure, and their importance:

  • Serum Creatinine:
    • What It Measures: Creatinine is a waste product from the normal muscle metabolism, normally filtered out by the kidneys. The serum creatinine test measures the level of creatinine in the blood.
    • Importance: Elevated creatinine levels indicate impaired kidney function or kidney disease. It's a primary marker for assessing kidney health.
    • Normal Range: Typically, 0.6 to 1.2 mg/dL for men and 0.5 to 1.1 mg/dL for women, though ranges can vary slightly between labs.
  • Blood Urea Nitrogen (BUN):
    • What It Measures: BUN measures the amount of nitrogen in the blood that comes from the waste product urea. Urea is made when protein is broken down in the body.
    • Importance: High BUN levels can indicate reduced kidney function, as the kidneys are not able to filter urea efficiently. However, factors like diet and hydration can also affect BUN levels.
    • Normal Range: Generally 6 to 24 mg/dL, but it can vary based on age and other factors.
  • Estimated Glomerular Filtration Rate (eGFR):
    • What It Measures: The eGFR estimates the rate at which the kidneys filter blood, based on serum creatinine levels, age, sex, and race.
    • Importance: eGFR is a crucial indicator of kidney function. Lower eGFR values suggest reduced kidney function or chronic kidney disease (CKD).
    • Calculation and Ranges:
      • Normal: 90 mL/min/1.73 m² or higher
      • Mildly decreased: 60-89 mL/min/1.73 m²
      • Moderately decreased: 30-59 mL/min/1.73 m²
      • Severely decreased: 15-29 mL/min/1.73 m²
      • Kidney failure: Less than 15 mL/min/1.73 m²
  • Additional Kidney Function Indicators:
    • Electrolytes and Minerals:
      • Potassium and Sodium: Imbalances can indicate impaired kidney function.
      • Calcium and Phosphorus: Abnormal levels often accompany kidney disease, impacting bone health.
    • Albumin: Low blood levels or high urine levels (albuminuria) can signal kidney damage.
    • Cystatin C: An alternative marker to creatinine for estimating GFR, particularly useful in specific populations where creatinine measurements might be misleading.
  • Role in Diagnosing Kidney Diseases:
    • Chronic Kidney Disease (CKD): Blood tests help in the early detection and staging of CKD, which is crucial for managing and slowing disease progression.
    • Acute Kidney Injury (AKI): Rapid increases in creatinine and BUN levels indicate AKI, necessitating immediate medical attention.
    • Monitoring Treatment Efficacy: Routine blood tests monitor the effectiveness of treatments for kidney disease and adjust therapies as needed.

Overall Importance:

  • Early Detection: Routine blood tests enable early detection of kidney issues before symptoms appear, facilitating timely interventions.
  • Monitoring Progression: Regular testing helps track the progression of kidney disease and the effectiveness of treatment plans.
  • Guiding Treatment: Results guide clinical decisions, from medication adjustments to lifestyle changes aimed at preserving kidney function.

Recommended Tests:

  1. Serum Creatinine
  2. Blood Urea Nitrogen (BUN)






Is it Time for an ESR Test? Key Signs and Benefits

The Erythrocyte Sedimentation Rate (ESR) test is a blood test that helps detect inflammation in the body, which can be indicative of various medical conditions. Understanding when to take an ESR test is crucial for accurate diagnosis and effective treatment of conditions such as giant cell arteritis, rheumatoid arthritis, and infections. Recognizing the symptoms that warrant an ESR test ensures timely medical intervention, helping manage and mitigate potential health issues efficiently. This article will guide you through the importance of ESR testing and the convenience of getting tested through platforms like GetLabTest.com.

Read the article


Comprehensive Guide to Designing an Effective Corporate Wellness Program with GetLabTest.com

A well-designed corporate wellness program is pivotal in enhancing employee health, boosting productivity, and fostering a positive workplace culture. Such programs are not merely an additional perk but a strategic initiative that can lead to significant benefits for both employees and the organization. Improved health and well-being of employees can reduce absenteeism, lower healthcare costs, and increase overall job satisfaction, which in turn can lead to higher levels of productivity and engagement. Moreover, a strong wellness program can be a key differentiator in attracting and retaining top talent, showcasing a company's commitment to the holistic well-being of its workforce.

Read the article


10 Million on NHS Waiting Lists? Discover the Fast-Track Solution with AI Self-Pay Diagnostics

In recent years, the National Health Service (NHS) has faced mounting challenges in providing timely medical diagnostics to its patients. Lengthy wait times have become a norm, with some patients enduring weeks, or even months, to receive routine diagnostic tests such as blood tests and imaging. This delay can be attributed to a mix of factors including rising demand, staffing shortages, and finite resources. The COVID-19 pandemic exacerbated these issues, creating significant backlogs across all areas of care.

Read the article