Kidney Disease

Kidney disease refers to any condition affecting how well the kidneys work. Kidney diseases range from mild infections that can be treated with antibiotics to chronic (long-lasting) diseases that cause the kidneys to deteriorate and ultimately to stop working.

What Are the Kidneys?

The kidneys are a pair of bean-shaped organs located in the back of the abdominal cavity right above the waist. There is one on each side of the spinal column. The kidneys perform a number of functions, chiefly filtering the blood, removing wastes to create urine, adjusting the chemical and fluid balance in the body by controlling the concentration of urine, and participating in the control of blood pressure. The kidneys also are involved in regulating the effects of vitamin D on the body and in stimulating bone marrow to create new red blood cells. When the kidneys are damaged by disease, some or all of these functions can be impaired. When the kidneys do not function properly, a person can become very ill; when they fail to function at all, a person will die without treatment.

Is Kidney Disease a Common Health Problem?

Kidney disease is a major health problem in the United States. Over 3.5 million Americans are affected by some form of kidney disease. Over 300,000 Americans have end-stage renal disease (ESRD), the most severe form of kidney disease. In 1996 over 12,000 people received kidney transplants. Billions of dollars are spent each year treating kidney disease.

What Are the Different Types of Kidney Disease?

There are three main categories of kidney diseases:

• Congenital disorder are genetic or begin very early in life.
• Chronic disorders are long-lasting and may develop gradually over many years.
• Acute disorders occur suddenly, for example from a block-age of the kidney drainage system.

Congenital Disorders

People can be born with a kidney disorder, in which case it is called a congenital disease. For example, the two kidneys may be connected at their base to form a single horseshoe-shaped kidney. Some people have one kidney missing from birth, or two on one side, or two ureters (the tubes that carry urine from the kidney to the bladder) for one kidney. A person's body usually can adjust to these problems because people can function with one kidney.

Mild Conditions Can Become Serious

Chronic, or long-lasting, kidney diseases are very serious conditions because they cause the kidneys to deteriorate over time. Glomerulonephritis (glomer-u-lo-ne-FRY-tis) is a condition in which the filtering units of the kidneys called the glomeruli (glom-ER-you-li) become inflamed. It often accompanies other diseases such as diabetes ^* and high blood pressure, or it can develop as the result of a bacterial infection or immunologic disease.

Organ for transplant. If kidney disease leads to kidney failure, dialysis or kidney transplant may be necessary.

© 1996 Michelle Del SuerciolCustom Medical Stock Photo.

The immune system makes proteins called anti-bodies to fight infection. In glomerulonephritis these antibodies become trapped in the glomeruli causing them to become inflamed. Glomerulonephritis may be treatable, or it may progress and cause severe kidney damage. Cancer, or tumors in the kidneys, also over time can stop the kidneys from functioning properly. Eventually, many of these diseases lead to end-stage renal disease (ESRD), a condition in which the kidneys shut down.

Acute Kidney Failure

Acute, or sudden, kidney failure can be caused by many things, including injury that severely reduces blood flow, severe dehydration, exposure to chemicals and drugs that are poisonous to the kidneys, infections, tumors, and kidney stones.

Pyelonephritis (PY-el-o-ne-FRY-tis), or infection of the kidney, is a common type of acute kidney disease. Its symptoms can include pain in the back or abdomen, fever, and frequent or painful urination. It can be treated effectively with antibiotics. Another well known condition is kidney stones. Kidney stones are hard crystals made of chemicals that separate from the urine and build up in the kidney. Small kidney stones can pass out of the body on their own, but larger stones require a procedure that breaks them into smaller pieces so that they can leave the body in the urine. People may recover from these kidney diseases without permanent damage to the kidneys. However, if left untreated, these diseases can cause permanent damage and kidney failure.

How is Kidney Disease Diagnosed and Treated?

Disorders that affect the proper functioning of the kidneys may be diagnosed by a number of methods: blood tests, urinalysis, kidney imaging (such as x-rays and MRI scans ^* ), and renal (kidney) biopsy (taking a sample of tissues). These tests are used to determine the type and extent of kidney disease.

How kidney disease is treated depends on the underlying cause. For example, an infection might require antibiotics, but a tumor would require surgical removal. Chronic conditions can be treated with drugs to reduce symptoms when the disease cannot be cured. A restricted diet also may help alleviate symptoms. Complete kidney failure requires dialysis two or three times a week or a kidney transplant.

The kidneys are located on both sides of the spinal column just above the waist.