eGFR Calculator (CKD-EPI 2012 Cystatin C)

eGFR stands for Estimated Glomerular Filtration Rate. It's a crucial measure indicating how effectively your kidneys are filtering waste products from your blood. An eGFR blood test using Cystatin C involves measuring your serum Cystatin C level from a blood sample. Your age and sex are also key factors used by this eGFR calculator (with the 2012 CKD-EPI Cystatin C formula) to provide an accurate estimate of your overall kidney function. Understanding your eGFR is the first step to assessing your kidney health.

This eGFR calculator utilizes the 2012 CKD-EPI Cystatin C formula. This equation estimates Glomerular Filtration Rate (GFR) using serum Cystatin C, age, and sex. Cystatin C is considered by many to be a more sensitive marker of kidney function than creatinine in certain populations because its levels are less influenced by factors like muscle mass, age, and diet. The CKD-EPI 2012 Cystatin C formula is a validated method for providing a reliable eGFR value based on this marker.

Your eGFR levels offer valuable insights into your kidney health. An eGFR normal range is generally considered to be 90 mL/min/1.73m² or higher, which typically signifies normal kidney function, assuming no other signs of kidney damage are present (like protein in urine). A low eGFR (e.g., consistently below 60 mL/min/1.73m² for three months or more) can be an indicator of chronic kidney disease (CKD). The specific egfr meaning of your test results should always be discussed with your healthcare provider, as they can interpret your eGFR test in the context of your complete medical history. For instance, an eGFR blood test low result warrants further medical investigation. While a very high eGFR is less common and usually not a direct cause for concern, it should still be reviewed by a doctor. This eGFR calculator helps in understanding the different stages of kidney disease based on these levels, which are further detailed in the 'About eGFR' section of this page.

A low eGFR or an eGFR blood test low result signifies that your kidneys might not be filtering blood as efficiently as they should. There are several potential reasons for a persistently low eGFR. Common causes include chronic conditions like diabetes and high blood pressure (hypertension), recurrent kidney infections, polycystic kidney disease, autoimmune diseases (such as lupus nephritis) that affect the kidneys, or the use of certain medications that can impact renal function. It is vital to consult your doctor to determine the precise cause of a low eGFR and to discuss suitable management strategies and treatment options. Remember, this eGFR calculator is an estimation tool and not a substitute for professional medical diagnosis.

This eGFR calculator employs the 2012 CKD-EPI Cystatin C formula, which uses Serum Cystatin C as the primary biomarker along with age and sex. Creatinine-based eGFR calculators (like those using the 2021 CKD-EPI creatinine formula or older MDRD formula) use Serum Creatinine. Cystatin C levels are generally less affected by muscle mass and diet than creatinine levels, potentially offering a more stable or accurate GFR estimation in certain individuals, such as the elderly, amputees, or those with atypical muscle mass. However, both types of markers have their roles, and sometimes combined equations are used.

No, this specific eGFR calculator and the 2012 CKD-EPI Cystatin C formula are validated and intended for use in adults (individuals aged 18 years and older). They are not designed for pediatric use (children or adolescents). Furthermore, assessing kidney function during pregnancy requires specialized evaluation by a healthcare professional, as GFR levels can change significantly. Different GFR estimation formulas and clinical approaches are employed for children and pregnant individuals to ensure accurate assessment.

The recommended frequency for an eGFR blood test to monitor your eGFR levels varies based on your individual health profile, existing risk factors for kidney disease (such as diabetes, hypertension, a family history of kidney problems, or older age), and your doctor's specific advice. If you have already been diagnosed with kidney disease, your doctor will establish a regular monitoring schedule. For general health screening, or if you possess risk factors, routine blood work that includes an eGFR test might be part of your annual physical or periodic health check-ups. Always adhere to your doctor's recommendations regarding the appropriate testing frequency for your eGFR levels to maintain optimal kidney health.

Serum Cystatin C (Scys) is a small protein produced by all nucleated cells in the body at a relatively constant rate. It is freely filtered by the glomeruli in the kidneys and then reabsorbed and metabolized by the renal tubules, so it doesn't return to the blood. When kidney function declines, the filtration of Cystatin C decreases, leading to an increase in its level in the blood. This makes Serum Cystatin C a sensitive and reliable biomarker for estimating kidney function and is the key input (along with age and sex) for this eGFR calculator using the 2012 CKD-EPI Cystatin C formula.