Kidney failure BBC Health News Kidney failure is a serious disease which can have a major impact on life, and can ultimately be fatal. However, it can be successfully treated. What do the kidneys do? In order for blood to perform its essential functions of bringing nutrients and oxygen to the cells of the body, and carrying waste materials away from those cells, the chemical composition of the blood must be carefully controlled. The kidneys play a crucial role in this process by filtering the blood under high pressure and removing potential toxins, which are excreted from the body in the urine. Every day the kidneys filter the body's entire blood volume seven or eight times. What is kidney failure? When the kidneys start to fail, toxins are not filtered out of the blood, and start accumulate in the tissues. This can lead to a range of problems. Build up of two waste products, urea and creatinine, can lead to tiredness, weakness, loss of appetite and vomiting. Accumulation of acid generated during the body's metabolic processes can lead to a condition called metabolic acidosis. Failure to get rid of phosphate, causes the blood phosphate level to increase and calcium level to fall. When calcium level is low, bones will become brittle. The kidney may also lose its ability to produce erythropoietin, resulting in anaemia. Kidney failure is also associated with an increase in the volume of water in the body which can result in a swelling of the tissues. Excess salt and water retention may cause high blood pressure, swelling of the legs, face, abdomen and breathlessness. What causes kidney failure? The common causes of kidney failure are glomerulonephritis (inflammation of the kidney) and diabetes mellitus. Other causes of kidney failure are kidney stones, kidney cysts, an immune disorder called systemic lupus erythematosus, uncontrolled high blood pressure and drugs. What are the symptoms? As the kidneys begin to fail the following symptoms can begin develop: pale and sallow complexion fatigue shortness of breath body itch poor appetite, sometimes accompanied with nausea and vomiting swelling of the face and legs disruption of urination patterns How is it treated? The most common treatment is by dialysis, a technique which artificially mimics the action of the kidneys. What is dialysis? There are two types of dialysis. Haemodialysis is the most frequently prescribed type of dialysis treatment. It involves circulating the patient's blood outside of the body through a series of tubes. The blood is filtered in a way similar to that used by the kidneys by using a chemical bath to draw out waste products. Most haemodialysis patients require treatment three times a week, for an average of 3-4 hours per dialysis. Less common is a technique known as peritoneal dialysis, in which the lining of the abdomen acts a blood filter. Is a transplant an option? For the right patient at the right time, a transplant is the best treatment for kidney failure. If it works well the patient will be totally free from dialysis. Many patients with kidney failure are suitable for a transplant.