Acute Renal Failure: Sudden Loss of Kidney Function

Acute renal failure, also known as acute kidney injury, occurs when the kidneys can no longer filter waste products from the blood. It usually develops rapidly, within hours to a few days. The condition is sometimes fatal, though it is reversible with intensive treatment.

Overall Causes

Acute renal failure can develop as a result of several events that impact kidney function. Anything that limits or slows blood flow to the kidneys can lead to this event. These causes are known as prerenal.Intrinsic or renal events damage the kidney itself to trigger acute kidney failure. Postrenal causes are those that block the kidney’s ureters, which drain urine.

Prerenal or Poor Blood Flow

Many conditions can affect the flow of blood to the kidneys. Cardiac issues, like heart attacks and heart disease, are both causes and results of kidney failure.Blood pressure medications, nonsteroidal anti-inflammatory drugs, and similar drugs can have side effects that impair blood flow, as well. Serious allergic reactions, severe burns, and extreme dehydration are also sometimes responsible.

Intrinsic, Renal, or Kidney Damage

Intrinsic causes of acute kidney injuries can be anything from blunt trauma to a disease that damages the kidney itself.Some conditions capable of doing this are acute tubular necrosis, acute interstitial nephritis, glomerulonephritis, and tumor lysis syndrome. In some cases, medications can damage the tubular cells of the kidney, resulting in acute renal failure.

Postrenal or Urine Blockage

The ureters are smooth tubes of muscle that help transfer urine from the kidneys to the bladder. Several issues can impact their function, causing acute renal failure. Kidney stones is one of the most common of these problems.Some people are born with atypical ureters, which can impede urine flow. Growths like tumors or endometriosis, as well as long-term swelling, are also sometimes the cause.

Risk Factors

Acute renal failure typically occurs alongside another medical issue. Factors that may increase the risk include:

  • Older age
  • Heart disease
  • High blood pressure
  • Receiving intensive treatment in a hospital
  • Peripheral artery disease, or blockages within the blood vessels in the arms and legs
  • Kidney disease
  • Liver disease
  • Cancer
  • Cancer treatments


Acute kidney failure has a few possible complications. Among the most common is edema, also known as fluid buildup. This can cause shortness of breath. Some people experience chest pain because the lining that covers the heart becomes inflamed. Muscle weakness can also occur when kidney failure affects the body’s balance of fluids and electrolytes. Acute renal failure can cause permanent kidney damage, which may require permanent dialysis or a transplant. These complications, as well as the condition itself, are sometimes fatal.


Because of its somewhat sudden nature, acute renal failure can be difficult to predict and prevent. Avoid taking excess amounts of nonsteroidal anti-inflammatory drugs and discuss the potential side effects of any prescription medications with a healthcare provider.People with chronic conditions which may contribute to renal failure should work with a doctor to stay healthy. Eating a healthy diet and avoiding alcohol can keep the heart and liver healthy, which helps prevent kidney issues.


Physicians have a few methods of diagnosing acute kidney injuries. Observing signs and symptoms is usually the first step. Tests to measure serum creatinine and urine output are also common.Doctors may also use urine microscopy and urine electrolyte tests. Doctors typically order renal ultrasounds if they suspect a renal or postrenal cause. In cases where the underlying trigger is unclear, the patient will need a kidney biopsy.

Treating Acute Renal Failure

To resolve acute renal failure, physicians must first identify and treat the underlying cause. The treatment varies depending on the triggering issue. For example, options for prerenal acute renal failure include the administration of IV fluids and medications to increase blood pressure.Intrinsic causes require far more specific therapies. Doctors can resolve postrenal causes by removing the obstruction or using renal replacement therapy.

Treating Complications

Because of how dangerous complications could be, doctors will often treat them as they develop. IV fluids can help relieve some of the issues, though diuretics (water pills) may be necessary in cases featuring edema. Medications to control blood potassium levels can prevent muscle weakness and irregular heartbeats. Dialysis may be necessary in some circumstances to remove dangerous toxins.