Renal, or kidney, disease is often a slow and insidious disease process. Most of the time, people with early kidney disease have no symptoms and are unaware that their kidneys are starting to fail. There are five stages of chronic kidney disease, defined by the change in glomerular filtration rate (GFR), which measures how well the kidneys are removing waste from the blood. The National Kidney Foundation states that 20 million Americans have some degree of kidney failure; diabetes and high blood pressure are frequent causes of renal disease.
Stage 1
In stage 1 renal disease, the GFR is unchanged from a normal level, which is greater than 90 milliliters per minute (mL/min). A person with stage1 renal disease generally has high blood pressure and elevated levels of creatinine or urea, waste products normally eliminated by the kidney, in the blood. Blood or protein, which are not normally found in the urine, may be found during urinalysis. Normally the kidney doesn't allow blood and protein to pass through its filters. Evidence of kidney damage may be seen on imaging scans such as MRI. Treatment at this stage is observation and management of any underlying disease.
Stage 2
The symptoms of stage 2 renal disease are similar to stage 1, but now normal kidney functioning begins to drop slightly. GFR in stage 2 is 60 to 89 mL/min. GFR of 60 to 89 mL/min is often seen in the elderly and very young infants, so age must be taken into account if no other signs of kidney disease are found, the National Kidney Foundation explains.
Stage 3
A moderate drop in GFR, down to 30 to 59 mL/min is seen in stage 3 of renal disease. Other signs of kidney disease in stage 3 include anemia, caused by the kidney's decreased ability to make erythropoietin, which stimulates red blood cell production and bone disease. Bone disease such as osteoporosis occurs because the kidneys normally keep calcium and phosphate, the main components of bone, in balance. Around 7.5 million Americans have stage 3 renal disease, according to DaVita.
Stage 4
At this stage, a person may begin to feel unwell, the Edinburgh Renal Unit states. Fatigue, appetite loss, nighttime urination and fluid retention are common. GFR drops to 15 to 29 mL/min. His doctor may begin talking about the possibility of dialysis to artificially cleanse the blood, or kidney transplant in the future. Around 400,000 Americans have stage 4 renal disease.
Stage 5
Stage 5 is kidney failure. GFR is less than 15mL/min, unless the person is on dialysis. Around 300,000 Americans fall into this category. Continued dialysis or kidney transplant are necessary to sustain life in stage 5 renal disease.
