The Creatinine Blood Test, including the estimated Glomerular Filtration Rate (eGFR), is used to assess kidney function. This test measures the level of creatinine, a waste product produced by muscle metabolism, in the blood. eGFR is a calculated value that provides an estimate of how well your kidneys are filtering blood. Together, these tests are critical for detecting early signs of kidney disease and monitoring kidney health over time.
What Is Creatinine?
Creatinine is a waste product produced when muscles break down creatine, a substance that helps supply energy to muscles. Normally, creatinine is filtered out of the blood by the kidneys and excreted through urine. Elevated creatinine levels in the blood can indicate poor kidney function or damage, as the kidneys are unable to efficiently remove this waste product.
What Is eGFR?
eGFR is a calculated value that estimates the glomerular filtration rate, a measure of how well your kidneys are filtering waste from your blood. It is calculated using the creatinine level, along with factors such as age, sex, and race. A normal eGFR indicates healthy kidney function, while a reduced eGFR may suggest kidney disease.
Why Is the Creatinine and eGFR Test Performed?
This test is commonly ordered to:
- Assess kidney function and monitor for signs of kidney disease, such as chronic kidney disease (CKD).
- Monitor kidney health in individuals at risk of kidney disease, including those with diabetes, high blood pressure, or a family history of kidney problems.
- Evaluate kidney function during and after treatment for kidney-related conditions, such as dehydration or kidney infections.
- Guide treatment decisions in patients with kidney conditions.
Symptoms That May Lead to a Creatinine and eGFR Test
Your doctor may recommend this test if you have symptoms that may indicate kidney problems, such as:
- Swelling in the legs, ankles, or face
- Fatigue or weakness
- Shortness of breath or difficulty breathing
- Changes in urination (e.g., more frequent or less frequent urination)
- High blood pressure or worsening hypertension
- Pain or discomfort in the lower back or abdomen
How Is the Test Conducted?
- Sample Collection: A healthcare provider will draw a blood sample, usually from a vein in your arm.
- Lab Analysis: The sample is tested to measure creatinine levels, and eGFR is calculated based on the results.
- Results Interpretation:
- Normal Creatinine Levels: Typically 0.6 to 1.2 mg/dL, though this can vary based on age, gender, and muscle mass.
- Normal eGFR: A normal eGFR is usually above 90 mL/min/1.73m². Lower values suggest reduced kidney function.
Common Conditions Linked to Elevated Creatinine or Low eGFR
- Chronic Kidney Disease (CKD): Gradual loss of kidney function.
- Acute Kidney Injury (AKI): Sudden, temporary loss of kidney function.
- Diabetes or High Blood Pressure: Conditions that increase the risk of kidney damage.
- Dehydration or Kidney Infection: Both can lead to increased creatinine levels.
- Kidney Stones or Blockages: Can obstruct the normal flow of urine and affect kidney function.
Preparation and Risks
- Preparation: No special preparation is required for the test, though you may need to fast for 8–12 hours before the blood draw in some cases.
- Risks: The test involves a blood draw, which carries minimal risks, such as slight bruising or discomfort at the needle site.
To book please use the link below or call our friendly team on 01443 303003.
