Kidney Stones

Kidney stones have been around for a long time. Egyptian mummies over 7 millennia old have been found with kidney stones. According to the U.S. Centers for Disease Control and Prevention (CDC), more then a million people in the United states will have a kidney stone this year; one in ten of us will have a stone at some point in our lives; men tend to get kidney stones more then women.

Where do they form?

Kidney stones form in the kidney but they don't always stay there. According to the American Foundation for Urologic Disease, kidney stones can move, and most do, from the kidney down the ureter to the bladder and out the urethra. (Read about "The Urinary System") Your two kidneys are bean shaped organs about the size of your fist. They sit near the middle of your back just below the rib cage. The kidneys strain your blood, taking out waste products and extra water that become urine. It is stored in the bladder until you go to the bathroom.

Are all kidney stones the same?

They come in all shapes and sizes. They can be as small as a grain of sand or as large as a golf ball. They can be smooth or jagged and are usually yellow or brown. The American Foundation for Urologic Disease says there are four major types of kidney stones:

• Calcium - the most common type. Most people flush out unused calcium (Read about "Calcium") but sometimes there is a buildup of calcium in the blood. (Read about "Hypercalcemia") Too much calcium can increase the risk of this type of kidney stone. Some people who develop this type of stone have an inherited metabolic disorder that causes a buildup of calcium in the urine. Certain drugs, such as furosemide (a diuretic), antacids and steroids, also may cause excess calcium in the urine. Diseases such as hyperparathyroidism and kidney disease can increase the risks of this type of stone. (Read about "Parathyroid Glands" "Kidney Disease") Other imbalances, such as too much oxalate in the urine (potentially the result of too much vitamin C or not enough vitamin B), too much vitamin A or D (Read about "Vitamins & Minerals"), and a diet high in purine from meat, fish and poultry, can also result in excess calcium.
• Struvite - may form after a urinary tract infection (Read about "Urinary Tract Infections"). These stones are made up of magnesium and ammonia, and are more common in women.
• Uric acid - form from too much acid in the urine. According to the National Kidney and Urologic Disease and Information Clearinghouse (NKUDIC), people who eat a lot of meat are more susceptible to these. If you develop gout, you also have a higher risk of developing this type of stone. (Read about "Gout")
• Cystine - are rare. They are usually the result of cystinuria, a hereditary disease. (Read about "Genetics" "Family Health History") In cystinuria, excessive levels of an amino acid called cystine build up in the urine and forms stones, which can get stuck in the kidneys, ureters, or bladder.

How can I tell I have one?

The first sign of a kidney stone is usually extreme pain in the back or side. It happens when the stone starts to move down the urinary tract. NKUDIC says other signs follow:

• blood in the urine
• fever and chills
• vomiting and nausea
• urine that smells bad or looks cloudy
• burning sensation while urinating

How do they find a stone?

The most common diagnostic tools include:

• ultrasound which uses high frequency sounds waves (Read about "Ultrasound Imaging")
• intravenous pyelogram (IVP) which uses a contrast agent or dye with a series of x-rays (Read about "X-rays")
• CT scan (computerized tomography) which uses x-rays and a computer to create cross sectional images (Read about "CT Scan - Computerized Tomography")

If the stone isn't too large and isn't stuck, the American Foundation for Urologic Disease says most times it is allowed to pass naturally. You'll be asked to drink a lot of water and may be given painkillers, if you need them. You'll also be asked to save the stone so the doctor can figure out what kind you have. You can use a cup or a tea strainer to catch the stone. Get rid of the cup or strainer after you capture the stone.

What if it won't pass?

It doesn't always mean surgery. One of the more recent innovations in kidney stone removal is shock waves. The medical name is extracorporeal shock wave lithotripsy or ESWL. There are two types of machines. With one, you are in a tub of water, with the other you lie on a bed. Shock waves are used to basically blast the stone apart so it can pass out naturally.

If surgery is needed, NKUDIC says there are two types. One is so-called tunnel surgery. Its medical name is percutaneous nephrolithotomy. The surgeon makes a cut in the patient's back and tunnels into the kidney to remove the stone. The second uses an ureteroscope to come in via the urethra to find the stone and pull it out. (Read about "Endoscopy")

How do you avoid kidney stones?

According to the NKUDIC, the best prevention is lots of water. Up to 12 glasses a day are recommended. Water helps the kidneys flush things out of the system and avoid dehydration. (Read about "Dehydration") If you are overweight (Read about "Obesity"), it can also help to get your weight down to a normal level, as a high body mass index has also been linked to an increased risk of kidney stones. (Read about "Losing Weight" "Body Mass Index") Having high blood pressure can also increase your risk. (Read about "Hypertension: High Blood Pressure") In addition, your doctor will want to rule out any conditions you have that may have contributed to the formation of kidney stones. For example, if the parathyroid glands in your throat are producing too much parathyroid hormone, it can increase the amount of calcium in your urine. (Read about "Parathyroid Glands")

Talk to your doctor. If you've had a stone or maybe a family history (Read about "Family Health History"), your doctor may want to make some dietary suggestions.

Related Information:

    Polycystic Kidney Disease

    Kidney Disease