For clinicians

eGFR (CKD-EPI)

Unit
mL/min/1.73m²

What is eGFR (CKD-EPI)?

eGFR is an estimate of how well your kidneys filter your blood. It's calculated from your creatinine, age and sex. Well-functioning kidneys clear out waste products and keep your fluid balance in order. A healthy value is reassuring; higher is better here.

Clinical frame

Calculation

eGFR computed with the race-free CKD-EPI 2021 equation from serum creatinine, age and sex (mL/min/1.73 m²)

The glomerular filtration rate is the best overall measure of kidney function, but cannot be measured directly. Synapse estimates it with the race-free CKD-EPI 2021 equation from serum creatinine, age and sex. Age and sex serve as a surrogate for muscle mass, which makes the estimate more accurate than creatinine alone [1] [2].

An eGFR below 60 that persists for at least three months defines, together with albuminuria, chronic kidney disease. Higher values count as kidney damage only with additional signs such as albuminuria. Interpret the eGFR together with the ACR in the KDIGO risk matrix. A lower eGFR is gradually associated with death, infarction, stroke and heart failure [2] [3].

Genetic studies show that mildly to moderately reduced kidney function contributes causally to coronary disease [3]. The estimate is valid only in a stable state and is distorted by abnormal muscle mass, extreme protein intake, cirrhosis and some medicines. In case of doubt, combining it with cystatin C gives a more accurate picture [1].

What moves this value?

The value falls slightly over the years. Dehydration, blood pressure and muscle mass can temporarily affect a measurement.

Drinking enough, a healthy blood pressure and not too much salt support your kidneys. Discuss a falling trend calmly with your doctor.

Developed and reviewed with the Synapse medical advisory board.

References

  1. Levey, A. S., Grams, M. E. & Inker, L. A. Uses of GFR and Albuminuria Level in Acute and Chronic Kidney Disease. N Engl J Med 386, 2120–2128 (2022). doi.org/10.1056/NEJMra2201153
  2. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 105, S117–S314 (2024). doi.org/10.1016/j.kint.2023.10.018
  3. Gaziano, L. et al. Mild-to-Moderate Kidney Dysfunction and Cardiovascular Disease: Observational and Mendelian Randomization Analyses. Circulation 146, 1507–1517 (2022). doi.org/10.1161/CIRCULATIONAHA.122.060700

The colour zones are personal: they depend on age, sex, risk and history, and appear in the patient's own report.

Insights to discuss with the patient, not a diagnostic instrument.