Alternative names
Kidney failure - chronic; Chronic renal failure; Chronic renal insufficiency; CRF; Chronic kidney failure

Definition
Chronic renal failure is a gradual and progressive loss of the ability of the kidneys to excrete wastes, concentrate urine, and conserve electrolytes

Causes, incidence, and risk factors

Unlike acute renal failure with its sudden reversible failure of kidney function, chronic renal failure is slowly progressive. It most often results from any disease that causes gradual loss of kidney function. It can range from mild dysfunction to severe kidney failure. Progression may continue to end-stage renal disease (ESRD).

Chronic renal failure usually occurs over a number of years as the internal structures of the kidney are slowly damaged. In the early stages, there may be no symptoms. In fact, progression may be so gradual that symptoms do not occur until kidney function is less than one-tenth of normal.

Chronic renal failure and ESRD affect more than 2 out of 1,000 people in the United States. Diabetes and hypertension are the two commonest causes and account for approximately two thirds of the cases of chronic renal failure and ESRD. Other major causes include the follow

 
• Glomerulonephritis of any type (one of the most common causes)  
• Polycystic kidney disease  
• Alport syndrome  
• Reflux nephropathy  
• Obstructive uropathy  
• Kidney stones and infection  
• Analgesic nephropathy

Chronic renal failure results in the accumulation of fluid and waste products in the body, causing azotemia and uremia. Azotemia is the buildup of nitrogen waste products in the blood. It may occur without symptoms. Uremia is the state of ill health resulting from renal failure. Most body systems are affected by chronic renal failure. Fluid retention and uremia can cause many complications.

Symptoms
Initial symptoms may include the following:

 
• Unintentional weight loss  
• Nausea, vomiting  
• General ill feeling  
• Fatigue  
• Headache  
• Frequent hiccups  
• Generalized itching (pruritus)

Later symptoms may include the following:

 
• Increased or decreased urine output  
• Need to urinate at night  
• Easy bruising or bleeding;  
• May have blood in the vomit or in stools  
• Decreased alertness       o drowsiness, somnolence, lethargy       o confusion, delirium       o coma  
• Muscle twitching or cramps  
• Seizures  
• Uremic frost - deposits of white crystals in and on the skin  
• Decreased sensation in the hands, feet, or other areas

Additional symptoms that may be associated with this disease:

 
• Excessive nighttime urination  
• Excessive thirst  
• Abnormally dark or light skin  
• Paleness  
• Nail abnormalities  
• Breath odor  
• High blood pressure  
• Loss of appetite  
• Agitation

Signs and tests
Blood pressure may be high, with mild to severe hypertension. A neurologic examination may show polyneuropathy. Abnormal heart or lung sounds may be heard with a stethoscope.

A urinalysis may show protein or other abnormalities. An abnormal urinalysis may occur 6 months to 10 or more years before symptoms appear.

 
• Creatinine levels progressively increase.  
• BUN is progressively increased.  
• Creatinine clearance progressively decreases.  
• Potassium test may show elevated levels.  
• Arterial blood gas and blood chemistry analysis may show metabolic acidosis.

Changes that indicate chronic renal failure, including both kidneys being smaller than normal, may be seen on:

 
• renal or abdominal X-ray  
• abdominal CT scan  
• abdominal MRI  
• abdominal ultrasound.

This disease may also alter the results of the following tests:

 
• urinary casts  
• renal scan  
• PTH  
• serum magnesium - test  
• erythropoietin

Treatment
Treatment focuses on controlling the symptoms, minimizing complications, and slowing the progression of the disease.

Associated diseases that cause or result from chronic renal failure must be controlled. Hypertension, congestive heart failure, urinary tract infections, kidney stones, obstructions of the urinary tract, glomerulonephritis, and other disorders should be treated as appropriate.

Blood transfusions or medications such as iron and erythropoietin supplements may be needed to control anemia.

Fluid intake may be restricted, often to an amount equal to the volume of urine produced. Dietary protein restriction may slow the build-up of wastes in the bloodstream and control associated symptoms such as nausea and vomiting. Salt, potassium, phosphorus, and other electrolytes may be restricted.

Dialysis or kidney transplant may be required eventually.

Support Groups
The stress of illness can often be helped by joining a support group where members share common experiences and problems. See kidney disease - support group.

Expectations (prognosis)
There is no cure for chronic renal failure. Untreated, it usually progresses to end-stage renal disease. Lifelong treatment may control the symptoms of chronic renal failure.

Complications

 
• End-stage renal disease  
• Pericarditis  
• Cardiac tamponade  
• Congestive heart failure  
• Hypertension  
• Platelet dysfunction  
• Loss of blood from the gastrointestinal tract  
• Ulcers  
• Hemorrhage  
• Anemia  
• Hepatitis B, Hepatitis C, liver failure  
• Decreased functioning of white blood cells  
• Decreased immune response  
• Increased incidence of infection  
• Peripheral neuropathy  
• Seizures  
• Encephalopathy, nerve damage, dementia  
• Weakening of the bones  
• Fractures  
• Joint disorders  
• Changes in glucose metabolism  
• Electrolyte abnormalities including hyperkalemia  
• Decreased libido, impotence  
• Miscarriage, menstrual irregularities, infertility  
• Skin dryness, itching/scratching with resultant skin infection

Calling your health care provider
Call your health care provider if nausea or vomiting persists for more than 2 weeks.

Call your health care provider if decreased urine output or other symptoms of chronic renal failure occur.

Prevention
Treatment of the underlying disorders may help prevent or delay development of chronic renal failure. Diabetics should control blood sugar and blood pressure closely and should refrain from smoking.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.