|
Glomerular filtration is the process by which the kidneys filter the
blood, removing excess wastes and fluids. Glomerular filtration rate (GFR) is used to determine how well the blood is filtered by the kidneys. It is one way to measure
remaining kidney function and it is the best test to measure the level of kidney function and to determine the stage of kidney disease.
GFR is calculated using a mathematical formula that compares your age, sex, and race to your serum creatinine levels. The normal GFR in both kidneys in adults is 120 to 125
mL/min. The lower the GFR number, the worse the kidney function. Here are the descriptions of the factors in the calculation:
- Serum creatinine: Usually between 0.8 and 1.6, but may be higher or lower. It measures waste product in the blood that comes from muscle activity. The kidneys normally
remove creatinine from the blood. As kidney function slows down, creatinine level goes up.
- Age: GFR decreases with age.
- Gender: Men usually have more muscle mass than women, so the calculation is adjusted.
- Race: Blacks tend to have more muscle mass than other ethnicities, so the calculation is adjusted.
|
5 Stages of Chronic Kidney Disease
|
|
|
Stage
|
Description
|
Glomerular
Filtration Rate GFR)
|
|
At increased risk
|
Risk factors
for kidney disease (e.g., diabetes, high blood pressure, family history, older age, ethnic group)
|
More than 90
|
|
1
|
Kidney damage (protein in the urine) and
normal GFR
|
More than 90
|
|
2
|
Kidney damage and mild decrease in GFR
|
60 to 89
|
|
3
|
Moderate decrease in GFR
|
30 to 59
|
|
4
|
Severe decrease in GFR
|
15 to 29
|
|
5
|
Kidney failure
(dialysis or kidney transplant needed)
|
Less than 15
|
|
|
