Symptoms of kidney failure may include an inability to urinate, swelling of the legs and feet, back pain, loss of appetite, and vomiting or nausea, according to WebMD. These symptoms are due to the kidneys failing to filter the blood properly and maintain the correct balance of fluids and electrolytes. The elderly have a higher risk of kidney failure - especially if they have other chronic illnesses, such as kidney or liver disease, high blood pressure, diabetes or obesity.
The early stages of kidney failure may produce no obvious symptoms, according to Medicine Net. The diagnosis of kidney failure is usually the result of blood tests showing that the kidneys are not operating properly. Kidney function naturally decreases as a person ages, and failure to control chronic medical conditions increases the likelihood of chronic kidney disease that can lead to kidney failure.
Reasons for kidney failure in those without previously existing kidney disease include reduced blood flow to the kidneys, a blockage of urine or long-term use of certain medications. Although kidney failure can be reversed in some cases, the elderly and those with serious health problems may not be able to regain kidney function, making long-term dialysis or transplant necessary, says WebMD.