Chronic Kidney Disease (CKD) indicates that a person’s kidneys are not functioning at full capacity. CKD is categorized into five stages, and determining the stage relies on measuring the Glomerular Filtration Rate (GFR).
Kidney function is assessed by the ability to filter blood effectively. GFR is a key indicator of a patient’s CKD stage, primarily determined by the level of creatinine in the blood. Blood tests measure serum creatinine, a waste product originating from muscle activity. Healthy kidneys eliminate creatinine from the blood. As kidney function declines, creatinine levels rise.
A mathematical formula calculates GFR, incorporating factors such as serum creatinine, age, and gender. Optional factors like weight, blood urea nitrogen (BUN), and serum albumin may also be considered for a patient’s GFR estimation. The GFR level establishes the stage of kidney disease, as illustrated below:
| GFR Level | Description |
|---|---|
| Stage 1 = 90 mL/min or more | Healthy kidneys or kidney damage with normal or high GFR |
| Stage 2 = 60 to 89 mL/min | Kidney damage and mild decrease in GFR |
| Stage 3A = 45 to 59 mL/min | Moderate decrease in GFR |
| Stage 3B = 30 to 44 mL/min | Moderate decrease in GFR |
| Stage 4 = 15 to 29 mL/min | Severe decrease in GFR |
| Stage 5 = Less than 15 mL/min or on dialysis | Kidney failure |
As CKD progresses, patients may experience additional issues like high blood pressure, anemia, malnutrition, bone disease, and nervous system problems. Accurate GFR levels enable doctors to provide appropriate treatment and medication dosages for each stage.
If your GFR calculator result is above 60 mL/min, it doesn’t necessarily indicate Stage 1 or Stage 2 CKD. Typically, Stages 1 and 2 have few symptoms and are diagnosed when other problems are present, such as:
Given that diabetes and high blood pressure are the leading causes of CKD, managing these conditions is crucial. Controlling blood sugar, blood pressure, prescribed medication, and limiting protein intake can help slow CKD progression.
In Stage 3 CKD, anemia and early bone disease may develop and should be treated to prevent future complications. As Stage 3 advances, consulting a nephrologist, a kidney disease specialist, is recommended.
By Stage 4 CKD, preparations for dialysis or kidney transplantation should begin. Patients should discuss hemodialysis and peritoneal dialysis options with their doctor to determine the best approach. If hemodialysis is chosen, a vascular access (fistula or graft) should be established in advance. Peritoneal dialysis requires catheter placement.
In Stage 5 CKD, the kidneys can no longer filter blood effectively, necessitating dialysis or kidney transplant for survival.
Disclaimer: Do not assume you have or do not have CKD based solely on GFR estimates; consult your doctor for a diagnosis. GFR estimates may not be reliable in certain cases. Factors other than CKD can influence GFR, including muscle trauma, vigorous exercise, high or low muscle mass (e.g., athletes or malnourished individuals), high or low dietary creatine (e.g., creatine supplement users or vegetarians), and possibly other conditions.
