A
kidney stone is a hard mass that forms when chemicals in the urine stick together to form crystals. These formed crystals vary in size from as small as a grain to as large as a golf ball. If the stones are tiny enough, they can easily pass through the urinary tract as part of the urine without even being noticed. Most kidney stones pass out of the body without special medical attention. However, stones that are large enough to cause symptoms or complications need physician intervention.
How common are kidney stones?Kidney stones are one of the most common disorders or diseases of the urinary tract. Almost 3 million people visit their healthcare provider and more than half a million people go to emergency rooms for kidney stone problems each year. Kidney stones are more common in men and its occurrence rises dramatically as they reach their 40s and continues to rise into their 70s. For women, the prevalence of kidney stones peaks in their 50s. [National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC), 2007]
Are all kidney stones the same?Kidney stones in the kidney, ureter, and bladder.
No. Kidney stones may contain various combinations of chemicals. The most common type of stone contains calcium in combination with either oxalate or phosphate. These substances are part of a person’s normal diet. They also make up important parts of the body, such as bones and muscles.
Other less common types of kidney stones include:
Stones caused by infection in the urinary tract called struvite or infection stones
Uric acid stones
Cystine stones (rare)
A person who gets more than one stone are more likely develop more stones.
Why are kidney stones more likely to form in some people and not others?Normally, urine contains chemicals that prevent crystals from forming. However, these chemicals do not seem to work for everyone.
Doctors do not always know what causes a stone to form. Some factors may contribute to stone formation in people who are susceptible to this disease. These factors include:
Urinary tract infections
A family history of kidney stones
Kidney disorders such as cystic kidney disease
Certain inherited (hereditary) and metabolic diseases such as renal tubular acidosis (inherited disease) and hyperparathyroidism (metabolic disease)
Misuse of certain medications and herbal supplements
While certain foods may promote stone formation in people who are susceptible, scientists do not believe that eating any specific food causes stones to form in people who are not susceptible. (NKUDIC, 2007)
What are the symptoms of kidney stones?Most kidney stones often do not cause any symptoms. If a small stone sits in the kidney without blocking the flow of urine, it usually does not cause pain. In addition, stones that are small enough can easily pass through the urinary tract in the urine.
Symptoms may occur as large stones move in the urinary tract. It includes:
Severe pain characterized as sharp, cramping pain in the back and side in the area of the kidney or lower abdomen, which may spread to the groin. (See Figure on the right. Pain in the shaded areas may be caused by a kidney stone.)(Image credit: NKUDIC)
Nausea and vomiting
Pinkish urine or blood in the urine
Burning feeling when urinating
A urine that smells bad or look cloudy
Fever and chills
If fever and chills accompany the other symptoms, it may mean that you have an infection. You should contact your doctor immediately.
How are kidney stones diagnosed?Often, the presence of kidney stones can be identified through X-ray or ultrasound. These diagnostic procedures are used to identify the size and location of the stones. To detect abnormal substances that promote stone formation, your doctor may require you to have blood and urine tests. These tests and procedures will help your doctor determine the proper treatment.
Kidney Stones Treatment. How are kidney stones treated?In most cases of kidney stones, surgery is not usually necessary. Most stones can be treated with drinking more liquids each day, dietary changes, and medications.
Drinking lots of water—about 2 to 3 quarts a day—will help move the stone along the urinary tract.
Other Treatment ProceduresExtracorporeal shock wave lithotripsy
Extracorporeal shock wave lithotripsy (ESWL)If the stones are large enough, a procedure called extracorporeal shock wave lithotripsy may be an option for treatment of kidney stones. It makes use of shock wave created outside the body. The shock waves break down the stone into small particles and can be easily passed through the urinary tract in the urine.
Sometimes the stone is not completely broken down with one treatment, and may require additional treatments.
Percutaneous NephrolithotomyIn this procedure, the surgeon makes a tiny incision in the back and creates a tunnel directly into the kidney.
Procedure: Percutaneous Nephrolithotomy
The surgeon uses an instrument called nephroscope to locate and remove the stone.
This procedure is often used when the stone is quite large or in a location that does not allow effective use of ESWL.
An advantage of percutaneous nephrolithotomy is that a surgeon can remove some of the stone fragments directly instead of relying solely on their natural passage from the kidney.
Uteroscopic Stone RemovalThis procedure does not require incision. Instead, the surgeon inserts a small wire-like instrument called a uteroscope through the urethra and bladder and into the ureter to locate the stone.
Procedure: Uteroscopic Stone Removal
The stone is removed with a small cage-like device in the uteroscope. Or the doctor may shatter the stone with a device inserted through the uteroscope that produces a form of shock wave. A small tube may be left in the ureter for few days to help with urine flow.
Although some stones in the ureters can be treated with ESWL, uteroscopic stone removal may be needed for mid and lower ureter stones.
**Ask your doctor which method is right for you.Can kidney stones be prevented?Drinking lots of water each day can prevent kidney stones. This makes the urine more diluted or less concentrated. Less concentrated urine decreases the concentration of chemicals or substances that may contribute to the formation of kidney stones. Water also helps to flush away these substances.
Before greatly increasing your fluid intake, you should consult your physician especially if you have other health problems.
If you have had kidney stones before, you are more likely to have others. Talk with your doctor about other ways to avoid more stones.
Diet changes can also help prevent formation of new stones. Sometimes this may be enough to prevent formation of stones. In some cases, diet and medications may be needed. Your doctor can determine which dietary changes and medications are right for you.
| Kidney and Kidney Stones (KKS) has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your primary health care provider. We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by Kidney and Kidney Stones. |
Reference: Scientific background provided by the National Kidney and Urologic Information Clearinghouse. NIDDK, NIH. NIH Publication No. 08–6186S/NIH Publication No.08–2495, October 2007, NIH Publication No. 07–4154, April 2007.
Image Credit: National Kidney and Urologic Information Clearinghouse. NIH Publication No. 08–2495, October 2007View the
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This Page Last Revised: June 07, 2008
