The different kidney disease stages classify renal failure according to the level of its severity. There are five (5) distinct categories, ranging from stage 1 to stage 5. These 5 categories help to determine the most effective treatment for patients with kidney disease.
Stage 1 is the mildest degree of kidney failure and at this stage the disease is hardly noticeable.
Stages 2 to 5 are classifications of chronic kidney disease that are progressively more severe. As kidney disease progresses from stage 2 to stage 5, kidney function declines.
Stage 5 is the most severe form of chronic kidney disease and is referred to as end stage renal disease (ESRD).
The time-frame in which kidney disease progresses from stage 1 to stage 5 can be extensive. In some cases it can take up to several months, or years, or sometimes decades for chronic kidney disease to move from sage 1 to stage 5 renal failure.
Basically, the degree of kidney failure is determined by the level of kidney function, and kidney function is primarily determined by the glomerular filtration rate (GFR).
GFR is the amount of filtrate that is formed per minute by the kidneys, as they filter the blood to remove waste products. GFR is used to determine the kidney disease stages.
During the process of filtering blood, there is an exchange of fluids and chemicals between the kidneys and blood plasma. Useful chemicals and fluids are returned to the blood plasma but waste products are converted to urine, which is subsequently expelled from the body.
The Glomerulus is the primary filtering unit of microscopic structures in the kidneys known as nephrons. As the Glomerulus filters the blood it forms a fluid called Glomerular filtrate. This fluid is similar to blood plasma except that it has almost no protein.
The diagram on the right provides an overview of the different kidney disease stages. Source: National Kidney Foundation.
The next two stages of kidney disease are classified as severe. Treatment for severe chronic kidney disease requires more than just diet, exercise and medication for underlying conditions.
The early stages of kidney disease can be detected by routine medical examinations. It is, therefore, advisable to have regular medical check-ups (at least once a year).
Early detection of chronic kidney disease provides the best opportunity for effective treatment, which can help to prevent or delay adverse outcomes associated with chronic kidney disease. The first two kidney disease stages (stages 1 and 2) offer the greatest possibilities for effective treatments.