Chronic kidney failure

Your kidneys are the key organs in the complex filtration system that removes excess fluid and waste material from the blood. Your kidneys receive blood through your renal arteries, which branch off the main artery (the abdominal aorta) carrying oxygenated blood away from your heart. On entering the kidneys, blood is distributed through smaller and smaller vessels, finally reaching tiny capillary blood vessels arranged in tufts (glomeruli).

The glomeruli filter your blood, extracting fluid, waste and substances your body needs — sugar, amino acids, calcium and salts. These filtered materials then cross into tiny tubules, from which the bloodstream reabsorbs what the body can reuse. The rest is waste, which is excreted in your urine.

Although your kidneys are usually able to clear all the waste products your body produces, problems can occur if blood flow to your kidneys is disrupted, if the tubules or glomeruli become damaged or diseased, or if urine outflow is obstructed.

Chronic kidney failure is a gradual loss of your kidneys' filtering ability, usually due to high blood pressure or diabetes. When kidney function is seriously impaired, dangerous levels of fluid and waste can quickly accumulate in your body.

In the early stages of chronic kidney failure, you may have few signs or symptoms. Many people with chronic kidney failure don't realize they have a problem until their kidney function has decreased to less than 25 percent of normal.

The main goal of treatment of chronic kidney failure is to halt or delay progression of the disease, usually by controlling the underlying cause. Chronic kidney failure can progress to end-stage kidney disease, which is fatal without artificial filtering (dialysis) or a kidney transplant.

Symptoms

High blood pressure

Decreased urine output or no urine output

Darkly colored urine

Anemia

Nausea or vomiting

Loss of appetite

Sudden weight change

A general sense of discomfort and unease (malaise)

Fatigue and weakness

Headaches that seem unrelated to any other cause

Sleep problems

Decreased mental sharpness

Pain along your side or mid to lower back

Muscle twitches and cramps

Swelling of the feet and ankles

Bloody or tarry stools, which could indicate bleeding in your intestinal tract

Yellowish-brown cast to your skin

Persistent itching

Causes

Progressive kidney damage most often results from a chronic illness over a period of years. Common causes include:

Diabetes. Diabetes mellitus is a leading cause of chronic kidney failure in the United States. Chronic kidney failure is related to both type 1 and type 2 diabetes.

High blood pressure (hypertension). Elevated blood pressure can damage the glomeruli and ultimately cause the nephrons containing damaged glomeruli to lose their ability to filter waste from your blood.

Obstruction of urine flow. An enlarged prostate, kidney stones or tumors, or vesicoureteral reflux — a condition that results when urine backs up into your kidneys from your bladder — can block urine flow, increasing pressure in your kidneys and reducing their function.

Kidney diseases. These include clusters of cysts in the kidneys (polycystic kidney disease), kidney infection (pyelonephritis) and inflammation of the glomeruli (glomerulonephritis), a condition that causes your kidneys to leak protein into your urine and damages nephrons.

Kidney artery stenosis. This is a narrowing or blockage of the kidney (renal) artery before it enters your kidney, which impairs blood flow and leads to kidney damage.

Toxins. Ongoing exposure to fuels and solvents, such as carbon tetrachloride, and lead — in lead-based paint, lead pipes, soldering materials, jewelry and even alcohol distilled in old car radiators  can lead to chronic kidney failure.

Others Related Topics