Kidneys are the organs that help filter waste products from the blood. They are also involved in regulating blood pressure, electrolyte balance, and red blood cell production in the body. Symptoms of kidney failure are due to the build-up of waste products in the body that may cause weakness, shortness of breath, lethargy, and confusion. Inability to remove potassium from the bloodstream may lead to abnormal heart rhythms and sudden death. Initially kidney failure may cause no symptoms. There are numerous causes of kidney failure, and treatment of the underlying disease may be the first step in correcting the kidney abnormality. Some causes of kidney failure are treatable and the kidney function may return to normal. Unfortunately, kidney failure may be progressive in other situations and may be irreversible. The diagnosis of kidney failure usually is made by blood tests measuring BUN, creatinine, and glomerular filtration rate (GFR). Treatment of the underlying cause of kidney failure may return kidney function to normal. Lifelong efforts to control blood pressure and diabetes may be the best way to prevent chronic kidney disease and its progression to kidney failure. As we age kidney function gradually decreases over time. If the kidneys fail completely, the only treatment options available may be dialysis or transplant.