Glomerular Filtration Rate (GFR)

A good GFR depends on age: in young adults a normal GFR is ≥90 mL/min/1.73 m². GFR declines with age (roughly 0.5–1 mL/min/1.73 m² per year), so values 60–89 may be expected in older adults if there’s no other kidney damage. GFR below 60 for three months suggests chronic kidney disease. Discuss results and urine tests with your clinician.

An estimated glomerular filtration rate (eGFR) below 15 mL/min/1.73 m² indicates kidney failure (stage 5 chronic kidney disease). At this level the kidneys cannot maintain fluid, electrolyte and waste balance; patients often need urgent specialist assessment and may require dialysis or transplantation. Diagnosis requires persistent low eGFR and clinical assessment, since single measurements can be affected by acute illness or lab variability.

A low GFR means your kidneys are filtering blood less effectively, indicating reduced kidney function. It can signal chronic kidney disease or acute kidney injury from causes like diabetes, high blood pressure, dehydration, medications, or blockage. Consequences include toxin and fluid buildup, electrolyte imbalances and progressive kidney damage. Further evaluation, treatment of underlying causes, monitoring and possibly specialist care are usually needed to prevent worsening.

GFR (glomerular filtration rate) measures how much blood your kidneys filter per minute, reported in mL/min/1.73 m². It indicates kidney function: normal is about 90–120 mL/min/1.73 m²; lower values suggest impaired function or chronic kidney disease and help stage severity. eGFR is estimated from serum creatinine, age, sex and race; factors like age and muscle mass also affect it.

Drinking adequate water helps maintain kidney perfusion and can restore or temporarily improve GFR if dehydration lowered it. In healthy people, staying well‑hydrated supports normal GFR, but excess drinking does not boost GFR long‑term or reverse chronic kidney disease. Overdrinking can be harmful in conditions like heart failure or advanced kidney disease; follow individual medical advice.

Serum creatinine is used to estimate GFR: higher creatinine usually indicates lower GFR. Creatinine itself doesn’t change kidney filtration, but decreased GFR leads to creatinine accumulation. eGFR calculations adjust creatinine for age, sex and body size because muscle mass, diet, hydration and some medications can alter creatinine independent of true kidney function, so interpretation needs clinical context.