What Is GFR?

Nephrologist working with a patient

The glomerular filtration rate, or GFR, measures how well your kidneys clean your blood. However, it’s not just about getting rid of waste and extra water; a test can also tell you if there are any problems with kidney function.

Glomeruli are a type of filter in the kidneys that remove waste from your system’s watery part-plasma membrane.

How Is the GFR Test Performed?

A lab specialist takes your blood sample and tests the level of creatinine, a chemical waste product that is made by muscles. Based on this reading and other factors such as age or weight, they use various formulas to estimate how strong your kidney function is. 

Understanding Normal Levels of GFR

Early-stage kidney disease doesn’t usually cause symptoms, but your doctor may recommend an eGFR test if you are more likely to develop kidney failure. Chronic kidney disease, or CKD, risk factors include having diabetes, being overweight, or having a family history of kidney failure.

Adults have different criteria than children because their bodies can process nutrients better in some areas. Your GFR number is an indicator of your kidney function. The GFR number goes down as kidney disease worsens.

  • A GFR of 60 or more is normal. This means that you may have a functioning kidney and do not need treatment, but you should still check with your doctor if it ever gets too low (below 60).
  • A lower number could indicate mild kidney disease that does not require immediate attention. But it could also be an indicator of moderate to severe cases, which can result in complete renal failure before anyone knows about them.
  • In adults, the standard eGFR number is more than 90. However, it declines with time as we age, even in people without kidney disease. Being aware of this can help you manage your chronic illness and prolong life by preventing complications down the road.

Stages of Chronic Kidney Disease and GFR Levels

  • Stage 1: A normal level of 90 or higher indicates healthy kidneys with minimal damage.
  • Stage 2: Kidneys can produce a slower GFR of 89 to 60, indicating kidney damage with a mild loss of function. A patient may experience fatigue, abdominal swelling, or nausea.
  • Stage 3: A GFR of 59 to 45 suggests mild kidney damage and the loss of function in this organ.
  • Stage 4: The severity of kidney function can be judged by measuring the amount of protein excreted in the urine. A GFR less than 44 indicates severe loss and may lead to problems later on down the line if not appropriately treated or prevented from happening at all through treatment like dialysis sessions.
  • Stage 5: If you have a GFR below 15, it is likely to lead to your kidneys becoming damaged. Kidney failure can be debilitating and may become life-threatening if left unchecked by appropriate treatment.

According to the CDC, 15% of American adults have chronic kidney disease

Kidney disease can have devastating consequences. Understanding the different stages of this illness could help you reduce its progression, maintain kidney health, and deal with any potential changes down the line.