Understanding Acute Kidney Failure: Causes, Symptoms, and Treatment

By Dr. Jatin Kothari in Nanavati Max Institute of Renal Sciences & Transplant , Kidney Stone Clinic , Kidney Transplant Unit , Kidney Dialysis Centre

Nov 24 , 2023 | 5 min read

Preventing acute kidney failure involves addressing the underlying causes and taking proactive measures to protect the kidneys from potential harm. It is a serious condition that requires prompt medical attention to prevent further complications and restore kidney function.

What is Acute Kidney Failure?

What is acute kidney failure? It is a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days. Also known as acute renal failure (AKI), this condition causes waste products to build up in your blood and makes it hard for your kidneys to keep the right balance of fluid in your body. It occurs when the kidneys are suddenly unable to filter waste products and excess fluids from the blood effectively.

Symptoms of Acute Kidney or Renal Failure

The signs of acute kidney failure vary depending on the underlying cause and the severity of the condition. Recognizing acute kidney failure symptoms early can be life-saving. Common symptoms of acute kidney failure include:

Decreased urine output (oliguria) or no urine output (anuria).
Swelling in the legs, ankles, or feet (edema) due to fluid retention.
Fatigue and persistent weakness.
Shortness of breath (dyspnea).
Nausea and vomiting.
Confusion or difficulty concentrating.
Chest pain or pressure.
Irregular heartbeat (arrhythmia).
High blood pressure.
Seizures or coma (in severe cases).

Emergency Warning: Seek immediate medical care if you experience sudden shortness of breath, persistent chest pain, or an inability to pass urine, as these are critical acute kidney failure symptoms.

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Acute Kidney Failure Causes: The Three Categories

The main cause of acute kidney failure is often classified into three categories based on where the damage originates: prerenal, intrinsic, and postrenal.

1. Prerenal: Decreased Blood Flow to the Kidneys

What causes acute renal failure most frequently is a lack of sufficient blood flow reaching the kidneys. Reasons for acute kidney failure in this category include:

Severe Dehydration: Significant fluid loss from vomiting, diarrhea, or excessive sweating.
Hemodynamic Instability: Conditions like severe blood loss, sudden low blood pressure (hypotension), heart failure, or severe infections (sepsis).

2. Intrinsic: Direct Damage to the Kidneys

Acute renal failure causes in this category involve direct injury to the kidney tissue itself:

Acute Tubular Necrosis (ATN): Damage to the tubular cells often due to prolonged ischemia or nephrotoxic medications.
Acute Glomerulonephritis: Inflammation of the glomeruli caused by infections or autoimmune disorders.
Medications and Toxins: An acute kidney failure cause can be linked to overuse of NSAIDs, certain antibiotics, or contrast agents used in imaging.

3. Postrenal: Urinary Tract Obstruction

What is the main cause of acute kidney failure when the issue is a "backup"? It is usually an obstruction in the urinary tract:

Blockages: Kidney stones, tumors, or an enlarged prostate gland that prevent urine from draining out of the body.

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How is Acute Kidney Failure Diagnosed?

To determine the best treatment for damaged kidney function, doctors must first diagnose the severity of the injury. Common diagnostic tests include:

Urinalysis: Checking for abnormal levels of protein or sediment.
Blood Tests: Measuring Serum Creatinine and Blood Urea Nitrogen (BUN) levels to calculate your Glomerular Filtration Rate (GFR).
Imaging: A Renal Ultrasound or CT scan to look for obstructions or structural changes.
Kidney Biopsy: In rare cases, a small tissue sample is taken to identify the specific renal failure causes.

Acute Kidney Failure Risk Factors

Advanced age, pre-existing chronic kidney disease (CKD), diabetes, and high blood pressure are significant risk factors. Additionally, being in an intensive care unit (ICU) or having a history of liver disease increases the likelihood of developing acute renal failure.

Kidney Failure Complications

Kidney failure complications can be life-threatening if not managed intensively. Common renal failure complications include:

Electrolyte imbalances: Specifically high potassium (hyperkalemia), which can lead to sudden cardiac arrest.
Metabolic Acidosis: Too much acid buildup in the blood.
Pulmonary Edema: Fluid in the lungs causing respiratory distress.
Uremia: A toxic buildup of nitrogenous waste affecting brain and heart function.

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Acute Kidney Failure Prevention

Preventing acute renal failure involves maintaining overall kidney health. This includes staying hydrated, managing diabetes, and avoiding nephrotoxic substances. If you are suffering from kidney stones, check out our recommended [kidney stone diet] to help protect your kidneys.

Kidney Failure Treatment and Recovery

The treatment for damaged kidney function focuses on treating the underlying cause (e.g., stopping a specific medication or treating an infection).

Dialysis: Hemodialysis may be used temporarily to filter the blood while the kidneys heal.
Medications: To manage blood pressure and electrolyte levels.

Kidney Failure Recovery: Unlike chronic disease, kidney failure recovery is possible in AKI if caught early. Many patients regain full function, though some may progress to permanent damage. Decisions regarding dialysis or long-term medication should always be made in consultation with a board-certified nephrologist.

What Medications are Used To Treat Kidney Failure?

Your medical team will choose medications depending on the reasons for acute kidney failure:

Diuretics: To reduce fluid retention.
Phosphate Binders: To control phosphorus levels.
Antihypertensives: To manage high blood pressure.

Medical Disclaimer: The information provided in this blog is for educational purposes only and should not be considered professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Frequently Asked Questions

1. How Long Can You Live with Acute Kidney Failure?

The prognosis for acute renal failure depends on the cause. If the underlying issue is treated quickly, many people live a normal lifespan. However, if complications like organ failure occur, the mortality rate increases significantly.

2. Can Acute Kidney Failure be Fixed? Can renal disease be cured?

When it is acute (AKI), the answer is often yes, provided there is no permanent scarring. Can a kidney disease be cured if it is chronic? Usually not, but acute damage is frequently reversible with hospital care and proper treatment for damaged kidney tissue.

3. What are the Warning Signs of Acute Kidney Failure?

What are the signs of acute kidney failure to watch for? The most common are sudden swelling in the extremities, a noticeable drop in urine frequency, and unexplained shortness of breath.

4. What are the 3 Types of Acute Renal Failure?

The three types are prerenal (blood flow issues), intrinsic (direct kidney damage), and postrenal (blockages in the urinary tract).

5. Is Acute Kidney Failure Painful?

The failure itself isn't always painful, but the causes of acute renal failure (like kidney stones or infections) can cause severe flank or abdominal pain.

References

1. Makris, K., & Spanou, L. (2016). Acute Kidney Injury: Definition, Pathophysiology and Clinical Phenotypes. The Clinical Biochemist Reviews, 37(2), 85–98. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5198510/

2. Goyal, A., Daneshpajouhnejad, P., Hashmi, M. F., & Bashir, K. (2023). Acute Kidney Injury. In StatPearls. StatPearls Publishing.
https://www.ncbi.nlm.nih.gov/books/NBK519012/