Kidney Failure

Definition

The kidneys remove waste in the form of urine from the body. They also balance the water and electrolyte content in the blood by filtering salt and water. When one or both of the kidneys are not able to perform these functions, kidney failure may result.

Kidney failure is divided into 2 categories:

• Acute kidney injury—sudden loss of kidney function
• Chronic kidney failure—slow, gradual loss of kidney function

Anatomy of the Kidney

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Causes

Kidney disease occurs when nephrons lose their ability to function normally. Nephrons are cells in the kidney that filter the blood. Damage to the nephrons may occur suddenly after an injury or poisoning. Many kidney diseases take years or even decades to cause damage that is noticeable.

The 2 most commons causes of kidney disease are:

• Diabetes—high blood sugar can damage nephrons
• High blood pressure—severe high blood pressure can damage blood vessels in the kidneys

Others causes include:

• Kidney infection—pyelonephritis
• Glomerulonephritis
• Genetic disorders, such as polycystic kidney disease
• Bilateral renal artery stenosis
• Birth defects
• Abnormal build-up of substances within the kidneys such as amyloidosis and protein build-up
• Toxic reaction to drugs or injections of contrast material used for imaging studies, such as CT scans

Risk Factors

Factors that increase your chance of kidney failure include:

• Chronic diseases that affect kidney function
• Genetic abnormalities or birth defects that affect kidney function
• Autoimmune disorders, such as systemic lupus erythematosus, polyarteritis , and Wegeners granulomatosis
• Cancer
• Severe trauma
• Viral infections, such as hepatitis B, hepatitis C, and HIV
• Long-term use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs), especially in high doses
• Conditions that affect blood volume, such as burns, pancreatitis, peritonitis, bleeding, and dehydration
• Conditions that make it difficult to urinate such as enlarged prostate, kidney stones, and tumors
• Recent heart surgery, such as open heart surgery or abdominal aortic aneurysm repair

Symptoms

Some kidney diseases begin without any symptoms. As the disease progresses, some of the following symptoms may develop:

• Fluid retention
• Swollen and numb hands and feet, itchy skin
• Fatigue and/or insomnia
• Low or no urine output
• Frequent urination
• Altered consciousness
• Loss of appetite, malnutrition
• Sores, bad taste in the mouth
• Nausea, vomiting
• Muscle cramps and twitches
• Shortness of breath
• High blood pressure
• Low temperature
• Seizures, coma
• Breath smelling like urine
• Yellowish-brownish skin tone

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluids and tissues may be tested. This can be done with:

• Blood tests
• Urine tests
• Biopsy

Images may be taken of your kidneys, bladder, and ureters. This can be done with a renal ultrasound or CT scan.

Treatment

Most chronic kidney diseases are not reversible, but there are treatments that may be used to help preserve as much kidney function as possible. In the case of acute kidney injury, treatment focuses on the illness or injury that caused the problem.

General Measures

• Restricting fluids
• Doing daily weight checks
• Eating a high-carbohydrate, low-protein diet

Medications

Medications used in acute or chronic kidney failure may include:

• Diuretics —to flush out the kidneys, increase urine flow, and rid the body of excess sodium
• Blood pressure medications
• Medications to treat anemia
• Sodium polystyrene sulfonate or insulin in dextrose to control high potassium levels
• Medications to control high phosphorus levels

Talk to your doctor about other medications you are taking. These include prescribed and over-the-counter medications, as well as herbs and supplements. Since the kidneys are no longer working properly, waste can build up in your body.

Dialysis

Dialysis is a process that takes over for the kidneys and filters waste from the blood. This may be needed until kidney function improves or a kidney transplant is done.

Kidney Transplant

This may be the right option for some people. Having a successful transplant depends on many factors, such as what is causing the kidney damage and overall health.

Lifestyle Changes

You can take the following steps to help your kidneys stay healthy longer:

• Have your blood pressure checked regularly. Take medication to control high blood pressure.
• If you have diabetes, control your blood sugar. Ask your doctor for help.
• Avoid the chronic use of pain medications.
• Depending on the severity of kidney disease, there may be dietary restrictions on protein, cholesterol, sodium, or potassium.

Prevention

In some cases, you cannot prevent kidney failure, but there are some steps you can take that will lower your risk:

• Maintain normal blood pressure.
• If you have diabetes, control your blood sugar.
• Avoid long-term exposure to toxic substances, such as lead and solvents.
• Do not abuse alcohol or over-the-counter pain medication.
• If you have chronic kidney failure, talk to your doctor before you become pregnant.