Kidney disease, also known as renal disease, can be classified into five stages based on the severity of kidney damage and the estimated glomerular filtration rate (eGFR), which measures how well the kidneys are functioning. Here is an overview of the stages of kidney disease:
Stage 1: Kidney damage with normal or increased eGFR
In this stage, there is evidence of kidney damage, such as presence of albumin (a type of protein) in the urine, abnormal kidney structure, or abnormalities in imaging tests. However, kidney function is still considered normal, and the eGFR is equal to or above 90 mL/min/1.73m².
Stage 2: Mildly reduced kidney function
In stage 2, there is mild kidney damage and a slightly decreased eGFR. The eGFR ranges from 60 to 89 mL/min/1.73m², indicating a slight reduction in kidney function. Symptoms may not be noticeable at this stage.
Stage 3: Moderately reduced kidney function
Stage 3 is further divided into two sub-stages:
- Stage 3a: The eGFR ranges from 45 to 59 mL/min/1.73m², indicating a moderate decrease in kidney function.
- Stage 3b: The eGFR ranges from 30 to 44 mL/min/1.73m², indicating a moderately severe decrease in kidney function.
During stage 3, symptoms may become more noticeable, and individuals may start experiencing complications associated with reduced kidney function.
Stage 4: Severely reduced kidney function
In stage 4, the eGFR ranges from 15 to 29 mL/min/1.73m², indicating a severe decrease in kidney function. Significant symptoms and complications often arise at this stage, such as fatigue, fluid retention, high blood pressure, anemia, and bone disease. Treatment options, including dialysis or kidney transplantation, may be considered.
Stage 5: Kidney failure (End-stage renal disease)
In the final stage of kidney disease, the eGFR is less than 15 mL/min/1.73m², indicating very low kidney function. This is known as end-stage renal disease (ESRD) or kidney failure. At this stage, the kidneys are unable to effectively perform their vital functions, and treatment options like dialysis or kidney transplantation are usually necessary to sustain life.
It is important to note that the progression of kidney disease can vary for each individual, and proper management, including lifestyle changes, medication, and regular medical care, can help slow down the progression and manage symptoms at each stage. Early detection and intervention are crucial for better outcomes.