Kidney function affects the entire body. Healthy kidneys filter wastes and excess fluid from the blood. They control blood pressure, affect bone density, and make hormones that trigger the production of red blood cells. Chronic renal failure (CRF) is an incurable disease causing progressive damage to the kidneys and irreversible loss of kidney function. Typical causes include diabetes and high blood pressure. Although treatment can slow kidney damage, deteriorating kidney function eventually becomes too poor to sustain life, resulting in end-stage renal failure, or ESRD.
Early Renal Failure
Chronic renal failure develops over decades. In the early phase, known as diminished renal reserve, some patients may experience more frequent urination as the kidneys lose some ability to concentrate urine. Often, however, at this stage there may be no symptoms because the healthy parts of the kidneys compensate for the damaged areas. At this stage, laboratory tests can detect impaired kidney function, allowing for diagnosis and treatment to delay further damage. In some cases, doctors may recognize early renal failure when another stress on the body, such as infection or dehydration, exposes the impaired kidney function.
Renal Insufficiency
As chronic renal failure progresses, not enough healthy areas remain to compensate for the damaged parts of the kidney. This stage of disease is called renal insufficiency because some, but not enough, function remains intact. Wastes begin to build up in the blood, and patients experience increased blood pressure, swelling, and other imbalances. Patients at this stage need treatment to control their symptoms and to delay further kidney damage. Doctors typically prescribe a low-salt, low-protein diet, and medications to minimize fluid retention and control blood pressure.
End-Stage Renal Disease
Eventually, progressive kidney damage leads to ESRD, which the Mayo Clinic defines as kidney function of less than 15 percent. In ESRD, many severe imbalances in the body put the patient at high risk for fatal complications. Extreme fluid overload and electrolyte imbalance causes stress on the heart, lungs, and other organs. Anemia, the lack of red blood cells, causes increased weakness. Build-up of wastes in the blood can cause mental changes, including lethargy, confusion, and even coma. When ESRD is reached, nothing can make the kidneys work well enough to maintain life. The only options are a kidney transplant or dialysis.
Dialysis
Patients with ESRD may be able to live for years with dialysis, which involves artificially filtering the blood of excess fluid and wastes. Although dialysis is a life-saving treatment, it is also a time-consuming, complicated procedure that carries serious risks, and it does not replace every aspect of kidney function. Treatment with medications usually continues with dialysis in order to trigger the production of red blood cells, maintain healthy bones, and control blood pressure.
Kidney Transplant
A kidney transplant surgically transfers a donor's healthy kidney into the patient with ESRD. Donors may be living or deceased. According to the American Kidney Fund, kidney transplants may be appropriate for some patients with ESRD if they do not have other serious health issues. However, there are many people waiting for kidneys and too few donors. Transplant recipients require lifelong medical treatment to prevent rejection of the new kidney.
