The kidney is a complex organ consisting of many different types of specialized cells, highly organized in a functioning unit called the nephron. The nephron may fail to perform its function due to diseases such as diabetes, hypertension, urinary tract infections etc. or other risk factors, family history, older age etc.
Once the damage of the kidneys starts, the process is ongoing and the kidney function tends to decline, even if the initial insult has been eliminated. This phenomenon is called progression of the CKD and typically moves from mild, moderate, to severe stages of diminution of renal reserve. By defining the stage of kidney disease
we aim at halting the progression or even make the disease regress through special medication, diet, change of life style etc. The 5 kidney disease stages reflect gradual adaptation in nephron loss and are the following:
• Stage 1: Normal GFR 90ml/min, or kidney damage with abnormalities in blood, urine tests or imaging studies.
• Stage 2: Kidney damage with mild reduction of GFR: 60-89 ml/min.
• Stage 3: Kidney damage with moderate reduction of GFR: 30-59ml/min.
• Stage 4: Kidney damage with severe reduction of GFR: 15-29ml/min.
• Stage 5: Kidney failure: GFR< 15ml/min.