What Are the Causes of Acute Kidney Failure?

Acute kidney failure is characterized by a sudden loss of kidney function. When acute kidney failure occurs the kidneys are not able to eliminate waste or excess electrolytes and fluid from the blood. When the kidneys are no longer filtering these things, dangerous levels of them build up in the body. Acute kidney failure has several causes and they are categorized by three types of conditions including prerenal conditions, postrenal conditions and renal conditions.

Conditions

• Prerenal conditions interfere with blood flow that is going to the kidneys. Postrenal conditions interrupt the filtering process by disrupting the excretion of waste through the urinary tract. Renal conditions result in direct damage to the kidney and its structures.

Causes

• Prerenal causes of acute kidney failure include extremely low blood pressure, low blood volume and poor heart function. Postrenal causes of acute kidney failure include ureter obstruction and bladder obstruction. Renal causes of acute kidney failure include toxic injury, reduced blood supply in the kidneys, inflammation in the kidneys and hemolytic uremic syndrome.

Symptoms

• Some of the symptoms of acute kidney failure come on suddenly and some are gradual. The symptoms of acute kidney failure include reduced output of urine (it may still be occasionally normal); confusion; fluid retention that may lead to swelling in the legs, feet or ankles; fatigue; shortness of breath; drowsiness; and chest pain. In severe cases coma and seizures can occur. If a patient's acute kidney failure is brought on by an underlying condition other symptoms may present themselves.

Risk Factors

• Risk factors for acute kidney failure include advanced age, certain blood disorders, chronic infection, heart failure, high blood pressure, diabetes, bladder outlet obstruction, certain immune disorders, enlarged prostate, liver diseases and kidney diseases. The majority of acute kidney failure cases are due to an underlying disease or risk factor.

Complications

• The sooner acute kidney failure and its cause are treated, the better the outcome. It can sometimes result in permanent loss of kidney function. In other cases, acute kidney failure can be fatal. Fatality is at its highest when a patient's kidneys fail after trauma, surgery or after a battle with chronic, severe medical problems.