A Glomerular Filtration Rate (GFR) result indicates how effectively your kidneys are operating. A value like 71 often raises questions about long-term health. The GFR is the primary tool providers use to evaluate kidney function and determine the presence and stage of chronic kidney disease. While this number suggests the kidneys are performing relatively well, it signals a need for careful attention and monitoring.
What Glomerular Filtration Rate Measures
The Glomerular Filtration Rate (GFR) estimates the volume of blood filtered by the kidneys’ glomeruli each minute. Glomeruli are tiny filtering units responsible for separating waste products, such as creatinine, from the blood. GFR is the standard measure of this filtration capacity, typically expressed in milliliters per minute per 1.73 square meters (mL/min/1.73 m²).
Measuring the true GFR directly is complex and impractical for routine clinical use. Therefore, a calculated estimate, known as the eGFR, is used instead. This estimate relies on a blood test measuring the concentration of creatinine, a waste product generated by muscle breakdown. The calculation combines the creatinine value with factors like age, sex, and sometimes race to produce the final eGFR number.
Interpreting a GFR Result of 71
A GFR of 71 indicates mildly decreased kidney function. The normal range for a healthy young adult is generally 90 mL/min/1.73 m² or higher, so 71 represents a slight reduction in filtering efficiency. This value falls within the range for Chronic Kidney Disease (CKD) Stage 2, which spans 60 to 89 mL/min/1.73 m².
Since the kidneys have a large functional reserve, a GFR of 71 usually causes no noticeable symptoms. The kidneys are still working well enough to prevent waste buildup and maintain the body’s fluid balance. A formal CKD Stage 2 diagnosis requires this mildly reduced GFR plus concurrent evidence of kidney damage. This evidence includes protein or blood in the urine, or structural abnormalities visible on imaging.
If the GFR is 71 without other markers of damage, the reduction may reflect the normal aging process. If signs of kidney damage are present, however, it confirms early-stage chronic kidney disease requiring consistent monitoring. Albuminuria, or protein in the urine, is an important marker indicating damage to the glomeruli and influencing the risk assessment for disease progression.
Factors Contributing to Mildly Decreased GFR
A GFR of 71 can result from chronic conditions or temporary influences. The most common chronic causes of mild GFR decline are poorly controlled high blood pressure and diabetes. Elevated blood pressure damages the small blood vessels in the kidneys over time. High blood sugar levels also strain the filtering units, gradually leading to reduced function.
Non-disease related factors frequently contribute to a GFR in this range. The estimated GFR naturally declines slightly with age, typically dropping about 8 mL/min/1.73 m² per decade after age 30. Therefore, a GFR of 71 in an older adult may be appropriate for their age, even without specific disease. Temporary conditions like dehydration cause a transient dip in GFR by affecting blood flow to the kidneys. Certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) used for pain relief, can also temporarily or chronically affect kidney function.
Next Steps for Management and Monitoring
A GFR of 71 requires consulting a healthcare provider for follow-up testing. The medical team typically repeats the GFR measurement after three months to confirm if the mild reduction is stable or persistent, which is necessary for a formal CKD diagnosis. They will also perform a comprehensive physical evaluation, including checking blood pressure and conducting a urine test for albuminuria.
Management focuses on lifestyle modifications to preserve remaining kidney function and prevent further decline. This includes maintaining optimal blood pressure control, often targeting below 130/80 mmHg, especially if diabetes or albuminuria is present. Dietary changes are advised, such as reducing sodium intake and highly processed foods to lessen the burden on the kidneys. Patients must use caution with certain over-the-counter medications, particularly NSAIDs, and ensure underlying conditions like diabetes are managed effectively to stabilize the GFR.