Causes of Kidney Failure

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Kidney Failure: What Is Kidney Failure?

Normal Kidney Anatomy Image
Normal Kidney Anatomy. Photo: National Institute of Health

What Is Kidney Failure?

Kidney failure is a condition where the kidneys are no longer filtering the blood of unwanted waste in the blood stream as well as they should.  This can happen for a variety of reasons, and ranges from a minor issue that is easily fixed to a life-long issue that requires dialysis to do the work of the kidneys.

Acute Kidney Failure

There are two primary types of kidney failure, acute and chronic.  

Acute kidney failure is a current and often sudden issue where the kidneys are not working as well as they usually do.  In many cases, acute issues with the kidneys that are treated quickly often completely resolve or cause minor issues with a return to near-normal function.  For some patients, an issue such as dehydration is present and the problem can be treated by something as simple as drinking more water or receiving IV fluids. 

The term acute technically means an illness less than six months in length, while chronic typically means six months or greater in length. 

Chronic Kidney Failure

Chronic kidney failure, the focus of this article, is also known as end-stage renal disease or ESRD. It is a condition where the kidneys lose their ability to filter waste and excess water from the bloodstream to convert into urine. Once the kidneys are so damaged that they cannot filter the blood enough to sustain life, the patient will require dialysis or a kidney transplant in order to live.

When the kidneys fail, dialysis -- a treatment where the blood is filtered and cleaned to do the work the kidneys cannot -- is performed. While dialysis can do the essential work of the kidneys, the treatment is expensive and time-consuming, requiring a minimum of three 3-hour treatments per week.

Kidney transplant surgery is the only “cure” for end-stage renal disease, as a functional kidney transplant will remove the need for dialysis. A transplant poses its own challenges but provides a great improvement in overall health when the surgery is successful.

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Diabetes and Kidney Failure

kidney bladder and inferior vena cava image
Image of Normal Urinary Tract. Photo © A.D.A.M.

Diabetes and Kidney Failure

Uncontrolled diabetes is the #1 cause of kidney failure in the United States, responsible for over 30% of the patients with the disease. The majority of kidney transplant recipients have either type 1 or type 2 diabetes.

Over time, high levels of glucose in the blood destroys the kidney’s ability to filter toxins and waste from the blood. The glucose molecule is larger than the molecules that the kidney is supposed to filter. The filtering mechanism is damaged as glucose is forced into the urine, and thus the kidney loses the ability to filter small molecules. The damage continues until it is so severe that waste begins to build up in the bloodstream.

Blood tests will typically show both elevated creatinine and BUN levels. When the waste begins to build up, dialysis or a kidney transplant is the next step for treatment.

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High Blood Pressure and Kidney Failure

High Blood Pressure Kidney Failure Image
High Blood Pressure and Kidney Failure. Photo: National Institutes of Health

High Blood Pressure and Kidney Failure

Hypertension, or high blood pressure, causes scarring of the kidney tissues. As the blood pressure rises, the kidneys try to compensate for the increasing pressure. Scar tissue accumulates over the course of months and years until the kidneys' ability to filter the blood is impaired.

Left untreated, high blood pressure continues to cause scarring in the kidneys until they fail and dialysis or a kidney transplant becomes necessary.

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Chronic Kidney Infections and Kidney Failure

Chronic Kidney Infections and Kidney Failure

Chronic kidney infections cause scarring of the kidneys, similar to the scarring caused by high blood pressure and diabetes. With each infection, the damage is increased, until the kidneys lose the ability to filter small particles from the bloodstream.

The more frequent and more serious the infections, the greater the likelihood that kidney failure will result. Urinary tract infections that are ignored can lead to kidney infections that persist until treated with antibiotics.

If enough infections are severe enough, or ignored and untreated, the result can be the need for dialysis or a kidney transplant.

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Polycystic Kidney Disease and Kidney Failure

polycystic kidney disease
Photo: National Institutes of Health

Polycystic Kidney Disease

There are two types of polycystic kidney disease (PKD). The first, Autosomal Dominant PKD (ADPKD), is a very common inherited disease -- a child has a 50% chance of inheriting the disease if either parent carries it. One in 500 newborns has ADPKD, which causes cysts to grow on the kidneys and leads to kidney failure in 50% of cases.

Autosomal Recessive PKD (ARPKD) is less common but is a far more severe form of the disease. Both parents must be a carrier for the disease, and their children have a 25% chance of having ARPKD. Approximately 1 in 20,000 newborns have the disease.

In this form of the disease, cysts grow inside the kidney, causing such severe damage that many patients die in the first month of life.

For those who survive, one-third will require dialysis by the age of 10. To make matters worse, children with ARPKD also have associated liver disease that can also cause life-threatening problems.

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Kidney Tumors and Kidney Failure

Kidney Failure and Kidney Transplants
CT Scan of Kidney Cysts. Photo: National Institutes of Health

Kidney Tumors and Kidney Failure

The growth of a tumor in the kidney, either cancerous or benign, can cause tremendous damage to the structures of the kidney. A typical adult kidney measures approximately 10 centimeters by 5 centimeters, yet tumors within the kidney can reach 10 centimeters in diameter or larger before the patient feels the slightest effects.

By the time the tumor is found, even if it is non-cancerous, the kidney may no longer be functioning. In some cases, the damage is so severe that the kidney must be removed to prevent damage to other organs, including the heart. If the remaining kidney is also not functioning well, dialysis or a kidney transplant may be required.

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Congenital Kidney Problems and Kidney Failure

Normal Kidney Blood Flow Image
Normal Kidney Blood Flow. Photo © A.D.A.M.

Congenital Kidney Problems and Kidney Transplants

A congenital kidney abnormality is a problem with the kidney that is present at birth. Abnormalities range from abnormal structures, blocked urine flow, unusual position of the kidneys that impairs function, or even being born with only one kidney. If the problem is severe enough, kidney failure may result.

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Kidney Stones and Kidney Failure

Image of Kidney Stones, Cause of Kidney Failure
Kidney Stone. Photo: National Institutes of Health

Kidney Stones and Kidney Blockages

Kidney stones, problems with the ureters (the tubes that allow urine to flow out of the kidney and into the bladder), and other conditions can prevent urine from draining from the kidneys. Typically, the problem begins in the kidney, but in some rare cases, the bladder cannot empty and urine will back up into the ureters, then into the kidneys.

Once the blockage is severe, the kidney becomes damaged as urine continues to be produced, but cannot flow out of the kidney. This condition can be extremely painful and may result in surgery to release the build-up of urine.

If the problem is left untreated, the kidney may no longer function and may even need to be surgically removed. In most cases, the undamaged kidney will be able to compensate; however, if the other kidney is also damaged, dialysis or a kidney transplant may be necessary.

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Risk Factors For Kidney Failure

Normal Urinary Tract Anatomy Image
Normal Anatomy of the Urinary Tract. Photo: National Institutes of Health

Kidney Failure: Who Is at Risk?

Studies have shown repeatedly that African-Americans are the most likely to need treatment for kidney failure, followed by Native Americans, then Asian/Pacific Islanders. Caucasians are the least likely to have end-stage renal disease, with rates of disease four times lower than blacks.

The difference in rates of disease is attributed to several things, including higher rates of diabetes in some races, access to health care, willingness to control diseases such as high blood pressure, and the ability to afford essential medications.

Men are slightly more likely to have kidney failure than women -- approximately 55% of patients are male. The rate of disease is highest between the ages of 45 to 64, an age when diabetes and other diseases have had decades to damage the kidneys.

Sources:

Diseases That Lead to Transplant. Transplant Living. 2008. http://www.transplantliving.org/beforethetransplant/diseases/default.aspx

Statistics, United States Renal Data System. 2007. http://www.usrds.org/2007/ref/A_incidence_07.pdf

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