Chronic kidney disease can lead to renal (kidney) failure, which is the point at which your kidneys no longer work. As kidneys start to fail, they lose their ability to remove fluids and waste products from the body. At first, the signs of renal failure, such as edema, fatigue and frequent urination, may be mild. Over a period of time, as the disease progresses and the kidneys no longer function properly, clinical signs worsen, and physical symptoms may become more obvious.
Edema
Edema is swelling that is caused by excess body fluids pooling up under the skin. When kidneys start to fail, fluid builds up in the face, legs, ankles, feet and hands. Your face may look puffy, and the swelling in your feet can be so bad that you cannot get your shoes on or have difficulty walking. Eventually, fluid retention can lead to congestive heart failure and fluid buildup in the lungs.
Pain
Headaches, muscle cramps and pain along the sides of your body and lower back, where the kidneys are located, may develop and worsen with progression of kidney disease. Bone fractures can occur because the kidneys normally regulate the actions of vitamin D and calcium, both of which are essential for keeping bones strong.
Urine Changes
Although the urge to urinate may occur more frequently--especially during the night--as kidney failure continues, urination becomes more difficult and produces less output. Urine may be foamy or dark in color, and the release of urine may cause burning or be accompanied by discharge.
Clinical Signs
The kidneys normally produce erythropoietin, a hormone that helps make red blood cells. In renal failure, production slows down and fewer red blood cells are produced. This can lead to iron-poor blood, or anemia. The first physical sign of anemia is often fatigue, because there are not enough red blood cells to carry oxygen throughout the body.
As kidneys fail and the body has a harder time eliminating fluids, blood pressure increases. This is one of the reasons why renal failure is associated with cardiovascular disease.
Glomerular filtration rate (GFR) measures the rate at which the kidneys filter and clean the blood. A GFR below 60 indicates kidney disease. As renal failure progresses, GFR continues to decrease.
Blood levels of the body chemicals urea nitrogen and creatinine are used to measure the progression of kidney disease from early stages on. Very high levels indicate end-stage renal failure. This means that the condition has progressed to the point where kidney damage is irreversible.
