Creatinine & eGFR

Creatinine is a muscle-metabolism waste product cleared by the kidneys; its blood level is used to estimate the glomerular filtration rate (eGFR), the standard measure of how well the kidneys filter.

eGFR is the primary way kidney function is tracked and chronic kidney disease is staged. Because creatinine depends on muscle mass, athletic or low-muscle individuals can be misclassified, which is why context and trends matter.

1. 1

   FoundationCardiovascular HealthThe best place to understand what actually prevents heart disease.
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   ConditionChronic Kidney DiseaseProgressive loss of kidney function
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   Signal RecordCreatineCreatine Monohydrate
4. 4

   Body SystemCardiovascularHeart function, blood pressure, and circulatory health.

1. Measure it
2. Understand your result
3. See what raises and lowers it
4. Apply evidence-based interventions
5. Recheck on your review cadence

An orientation to how this topic is typically approached — not medical advice.

A falling eGFR (rising creatinine) over time signals declining kidney function and prompts evaluation. Isolated mildly reduced eGFR in a muscular person may not indicate disease; persistence and other markers (e.g., albuminuria) clarify.

• Serum creatinine with calculated eGFR
• Cystatin C or urine albumin for confirmation

eGFR from creatinine is the validated standard for staging kidney function, with well-understood limitations addressed by cystatin C and albuminuria testing.

• KDIGO Clinical Practice Guideline for CKD Evaluation and Management
• National Kidney Foundation guidance

Sources are named authoritative guidelines and scientific bodies. Biomarker pages present established clinical context; calibrated evidence verdicts on specific interventions live in the linked Signal Records.