Kidney failure

A reduction in the function of the kidneys. Kidney failure can be acute or chronic. In acute kidney failure, kidney function often returns to normal once the underlying cause has been discovered and treated; in chronic kidney failure, function is usually irreversibly lost. Causes of acute kidney failure include a severe reduction in blood flow to the kidneys, as occurs in shock; an obstruction to urine flow, for example due to a bladder tumour; or certain rapidly developing types of kidney disease, such as glomerulonephritis. Chronic kidney failure can result from a disease that causes progressive damage to the kidneys, such as hypertension, longstanding obstruction to urine flow, and excessive use of analgesic drugs. The most obvious symptom of acute kidney failure is usually oliguria (reduced volume of urine). This leads to a build-up of urea and other waste products in the blood and tissues, which may cause drowsiness, nausea, and breathlessness. Symptoms of chronic kidney failure develop more gradually and may include nausea, loss of appetite, and weakness. If acute kidney failure is due to sudden reduction in blood flow, blood volume and pressure can be brought back to normal by saline intravenous infusion or blood transfusion Surgery may be needed to remove an obstruction in the urinary tract. Acute kidney disease may be treated with corticosteroid drugs. Treatment may also involve diuretic drugs and temporary dialysis (artificial purification of the blood). A high-carbohydrate, lowprotein diet with controlled fluid and salt intake is important for both types of kidney failure. Chronic kidney failure may progress over months or years towards end-stage kidney failure, which is life-threatening. At this stage, longterm dialysis or a kidney transplant is the only effective treatment.