A gradual and progressive loss of the ability of the kidneys to excrete wastes, concentrate urine, and conserve electrolytes .

Alternative Names

Kidney failure - chronic; Renal failure - chronic; Chronic renal insufficiency; CRF; Chronic kidney failure

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 . 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 end stage renal disease (ESRD) affect more than 2 out of 1000 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 glomerulonephritis of any type (one of the most common causes), polycystic kidney disease , Alport syndrome , reflux nephropathy , obstructive uropathy , kidney stones and infection, and analgesic nephropathy . Chronic renal failure results in the accumulation of fluid and waste products in the body, causing azotemia and uremia . Azotemia is the build-up 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 (see Complications).

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 .