Definition

Kidney diseases are disorders that affect the kidneys; the two organs that remove waste products, produce certain hormones, and regulate the level of chemicals in blood.

Description

Kidney Function

A major function of the kidneys is to remove waste products and excess fluid from the body. These waste products and excess fluid are removed through urine.

The production of urine involves highly complex steps of excretion and reabsorption. This process is necessary to maintain a stable balance of body chemicals.

The critical regulation of the body's salt, potassium, and acid content is performed by the kidneys. The kidneys also produce hormones and vitamins that affect the function of other organs. For example, a hormone produced by the kidneys stimulates red blood cell production. In addition, other hormones produced by the kidneys help regulate blood pressure and others help control calcium metabolism.

There are two kidneys, each about the size of a fist, located on either side of the spine at the lowest level of the rib cage. Each kidney contains about one million functioning units, called nephrons.

A nephron consists of a filtering unit of tiny blood vessels, called a glomerulus, attached to a tubule. When blood enters the glomerulus, it is filtered and the remaining fluid passes along the tubule. In the tubule, chemicals and water are either added to or removed from this filtered fluid, according to the body's needs, with the final product being the urine we excrete.

Types Of Kidney Disease

Kidney disease usually affects both kidneys. If the kidneys' ability to remove and regulate water and chemicals is seriously damaged by disease, waste products and excess fluid build up occur, causing severe swelling and symptoms of uremia (kidney failure).

There are many different types and causes of kidney disease. These can be characterized as hereditary, congenital or acquired.

Hereditary Disorders

These can be transmitted to both males and females, and generally produce clinical symptoms from teenage years to adulthood. The most prevalent hereditary kidney condition is polycystic kidney disease. Other hereditary conditions include Alport's syndrome, hereditary nephritis, primary hyperoxaluria and cystinuria.

Congenital Disease

This usually involves some malformation of the genitourinary tract, usually leading to some type of obstruction which subsequently produces infection and/or destruction of kidney tissue. The destruction can eventually progress to chronic kidney failure.

Acquired Kidney Disease

These diseases are numerous, the general term being nephritis (meaning inflammation of the kidney). The most common type of nephritis is glomerulonephritis, and again, this has many causes.

Kidney Stones

These are very common, and when they pass, the pain can be extremely severe in the side and back. Stone formation can be an inherited disorder, secondary to a malformation and/or infection in the kidney, or can occur without any prior problem. The pain can appear suddenly and in waves, and then disappear rapidly when the stone is passed.

Nephrotic Syndrome

This refers to a large protein loss in the urine [frequently in association with low blood protein (albumin) levels, an elevated blood cholesterol and severe retention of body fluid, causing swelling (edema)]. This disease can be a primary disorder of the kidney or secondary to an illness, affecting many parts of the body (for example diabetes mellitus).

Long-standing High Blood Pressure (hypertension)

This can cause kidney disease itself or can be a result of a kidney disorder. Uncontrolled high blood pressure can accelerate the natural course of any underlying kidney disease.

Diabetes

Long standing diabetes can lead to kidney failure. However, tight control of blood glucose levels over the years may reduce those complications.

Drugs and Toxins

Certain medications, toxins, pesticides and "street" drugs (i.e., heroin) can also produce kidney damage.

Causes and Risk Factors

Unfortunately, the cause of many kidney diseases is still unknown, but controlling high blood pressure and diabetes can reduce the risk of many kidney diseases.

Symptoms

Although many forms of kidney disease do not produce symptoms until late in the course of the disease, there are at least six warning signs that may indicate kidney disease:

1. Burning or difficulty during urination
2. An increase in the frequency of urination
3. Passage of blood in the urine
4. Puffiness around the eyes, swelling of the hands and feet
5. Pain in the small of the back just below the ribs
6. High blood pressure

Diagnosis

Your doctor will obtain a complete medical history and perform a physical exam. He or she may recommend blood tests and certain urine tests, which can provide much information about your kidney function.

Treatment

Some kidney diseases can be successfully treated and others progress to advanced kidney failure, requiring dialysis and/or transplantation.

For example, kidney infections and kidney stones can often be successfully treated. Chronic inflammation of the glomerulus (glomerulonephritis) is the most common kidney disease, which slowly progresses to kidney failure.

Your doctor may recommend certain medications or suggest a specific diet for you.

Questions to Ask Your Doctor

• Are there any tests that need to be done to diagnose the kidney problem?
• Are there any risks or side effects associated with these tests?
• What caused the problem?
• What type of kidney disease is it?
• How serious is this condition?
• What are the chances this could progress to kidney failure?
• What type of treatment will you be recommending?
• How effective is this treatment?
• What should be expected from this treatment?
• Are there any alternative treatments?
• Will you be prescribing any medication? What are the side effects?