Reviewed by Dr. Clement J. Cheng
The kidneys are fist-sized, bean-shaped organs located near the middle of the back. Their role within the body is to remove toxins and excess fluid. The kidneys process approximately 200 quarts of blood to sift out about 2 quarts of waste products (which come from normal breakdown of active muscle and food) and extra water daily. The waste and extra water become urine, which flows to the bladder through tubes called ureters. The bladder stores urine until it leaves the body.
When the kidneys become diseased or damaged, they may lose their ability to perform these functions. Toxins and excess fluids build up inside the body, and if left untreated, may lead to kidney failure. Loss of kidney function is a potentially fatal condition.
Symptoms of kidney disease include:
- Increased nighttime urination
- Passing of small amounts of urine
- Swelling of the hands and feet
- Puffiness around the eyes
- Urine-like breath
- Shortness of breath
- Loss of appetite
- Fatigue
- Increasingly higher blood pressure
- Excessively dry, itchy skin
Kidney disease can be classified in two ways: chronic or acute.
- Chronic kidney disease comes on gradually over several years and may not show symptoms until considerable damage to the kidneys has been done. Chronic kidney disease is most often the result of another condition, such as diabetes, high blood pressure, or atherosclerosis. All of these disorders impede the flow of blood within the kidneys.
Some chronic kidney diseases, such as polycystic kidney disease, are inherited. Others are congenital, or the result of a malformation a person is born with and that predisposes the person to kidney disorders.
Chronic kidney disease can also be the product of long-term exposure to toxic chemicals or drugs, such as heroin. Some doctors also believe that excess Vitamin D and protein in diets of the elderly or ill may harm the kidneys.
- Acute kidney disease develops within a matter of days after the onset of a medical condition, such as heart attack, injury, or infection, that reduces the flow of blood to the kidneys. Toxic reaction to a drug, inhaling toxins, and poisonous mushrooms, can also bring on kidney disease.
Kidney disease is diagnosed with blood tests, urine tests, and ultrasound. If the diagnosis is unclear after these tests, a biopsy of the kidney tissue may be required.
Kidney disease may be preventable. People should limit their intake of cadmium, a rare, naturally occurring metal used in the manufacture of pesticides, rubber tires, plastics, and paints. Because of its industrial uses, it is often found now in water and food supplies. Foods with high levels of cadmium include liver and kidney products, mussels, scallops, oysters, and flounder.
Take care around carbon tetrachloride, until recently a household solvent; chloroform, a sweet chemical found in the air and as a by-product of cholorination; ethylene glycol, a chemical found in antifreeze, brake fluid, and cosmetics; oxalic acid, used in heavy-duty household cleaning products; and tetrachloroethylene, the most widely-used dry-cleaning chemical in the United States.
Kidney disease can be treated with medication. Depending upon the severity of the particular kidney disease, several options exist. Most people receive a prescription for angiotensin-converting enzyme (ACE) inhibitors to keep blood pressure down and slow the rate of injury to the kidneys. Other prescribed medicine may lower potassium levels and block the stomach’s absorption of phosphorus.
If the patient’s red blood cell level falls, the doctor will prescribe a medication with an iron supplement. Calcium supplements also may keep bones from weakening, which is sometimes a side effect of kidney disease.
Dietary restriction is a controversial treatment for kidney disease. Some patients manage their disease by restricting proteins, which some doctors believe can delay or even prevent further kidney deterioration—especially for those whose kidney disease is the result of diabetes. Potassium, phosphorus, and sodium may also be limited. Dosing of medications should also be adjusted depending upon renal function.
If the kidneys fail, this is known as end-stage renal disease (ESRD). At this point, the kidneys function at less than 10 percent of their capacity. Without hemodialysis, peritoneal dialysis, or transplantation, serious complications ensue and the patient will die due to accumulation of fluids and waste in the body.
In the United States, almost 100,000 people are on chronic dialysis; more than 20,000 have a functioning transplanted kidney. Almost half the people with ESRD developed kidney disease through diabetes.
