Frequently Asked Questions
What are kidney stones?
What are the signs and symptoms of kidney stones?
What causes kidney stones?
Can kidney stones damage the kidney?
Who gets kidney stones?
What are the treatment choices?
What are the advantages of Lithotripsy?
Can kidney stones recur?
What can you do to prevent future kidney stones?
How long does the procedure take?
When can I go back to work?
When can I resume sexual relations?
What can a patient expect during a Lithotripsy treatment?
Why do I need a driver?
What is a stent?
Who determines if I need a stent?
How does the doctor put in the stent?
How long will the stent be in?
How do I know if I'm dehydrated?
My friend says that I should drink a lot of cranberry juice, is that true?

What are kidney stones?

The kidneys are the master chemists of the body. Normally, there are two of them, one on either side of the spine under the lower ribs. They are reddish brown in color and shaped like kidney beans. Each kidney is about the size of your clenched fist.


What are the signs and symptoms of kidney stones?

The pain begins as an ache in the back and side (the flank). Then it becomes constant and severe as the urinary system tries to rid itself of the stone. Sometimes there is burning during urination, blood in the urine, or a frequent urge to urinate. Nausea and vomiting may occur, and the lower abdomen or flank may be painful if touched. The pain has been described by some women as worse than natural child birth.


What causes kidney stones?

Kidney stones are hardened crystal clumps that can develop in the urinary system. They usually form because there is a breakdown in the balance of liquids and dissolved solids in the urine. The kidneys must keep the right amount of water in the body while they remove materials that the body cannot use. If this balance is disturbed, the urine can become overloaded with substances (usually small crystals) that won't dissolve in water. Crystals begin to stick together and slowly add layer upon layer to form a stone. A kidney stone may grow for months or even years before it causes a problem.

Experts suggest that age, diet, climate, infection and inherited disorders are some possible causes of kidney stones.


Can kidney stones damage the kidney?

Kidney stones can cause kidney damage. Whether there is damage and, if so, how much there is depends on the location of the stone in the urinary system. To avoid or minimize damage, it is important to eliminate stones that form and to prevent new ones from developing. Therefore, your family doctor may refer you to a urologist, a doctor who specializes in urinary diseases.


Who gets kidney stones?

Anyone can get kidney stones, but some people are more likely to develop stones than others. Typically, a person with a kidney stone is a man 20 to 60 years old. Although four out of five kidney stone sufferers are men, women also get kidney stones. Often, there is a family history of kidney stones. Chronic dehydration (lack of body water) can lead to kidney stones. Very hot weather, heavy sweating, or too little fluid intake contribute to the formation of kidney stones. People who work outdoors in hot weather and who do not drink enough fluids may increase their risk of getting stones.

Some physicians believe that our rich diet in the U.S. may promote the development of kidney stones. Experts note that the incidence of kidney stones has tripled in Japan since World War II - at the same time the Japanese diet has become more like our own.

A variety of other conditions are linked with kidney stone development. These include urinary tract blockage, urinary infections that recur, bowel disease, and certain inherited disorders. People who are paralyzed or who have to rest in bed for long periods of time are also at increased risk for kidney stones, as are men and women who fly long space missions.


What are the treatment choices?

How a particular stone is treated depends on its size, location and composition. Although kidney stones, especially calcium stones, are very hard, most of the 20% to 30% that do not pass out of the body on their own can be eliminated without surgery. A process called lithotripsy (from the Greek word for "stone crushing") breaks into tiny fragments most stones that are less than three-quarters of an inch across. (Lithotripsy is also called extra-corporeal shock wave lithotripsy.)

Lithotripsy has been used in the U.S. since 1984. A urologist performs the treatment using a machine called a lithotripter. It is the most common method of treating stones in the US. There are different types of lithotripters, but all focus shock waves from outside the body on the kidney stone. Repeated shock waves cause the kidney stone to disintegrate into tiny particles. These particles pass easily out of the body in the urine.

Lithotripsy alone doesn't work for all patients or for all kidney stones. Other treatment options include medication therapy, ureteral stent, ureteroscopy, percutaneous lithotripsy or open surgery. Please discuss these options with your urologist to determine which is best for you.


What are the advantages of Lithotripsy?

Lithotripsy offers many advantages over stone removal through surgery. Some of those advantages include:

1. Reduction in complications
2. Reduction in pain
3. Reduced recuperation time
4. Performed on outpatient basis 95% of the time
5. Able to resume normal activities much sooner
6. Reduced cost
7. No incision


Can kidney stones recur?

People who have had one kidney stone are prone to develop others. Without preventive treatment or changes in lifestyle, patients can develop a new stone within a year or two of the first one. About half of patients do develop a stone again within 5 to 10 years, and 80% do so sometime in their lives.


What can you do to prevent future kidney stones?

There definitely are things you can do to reduce your chances of developing another stone. One of the most important is simply getting into the life-long habit of drinking a lot of liquid - mainly water. Everyone who has had a kidney stone should drink at least 8 ounces of fluid at each meal, between each meal, before bed, and during the night if awakened to urinate. In other words, you should drink a minimum of 7, and preferably 10 to 12, large glasses of fluid in the course of each day. At least half of these should be glasses of water.

Your fluid intake should be spread out as evenly as possible throughout the day. This keeps the urine from becoming concentrated and reduces the chances that crystals - the building blocks of kidney stones - will form. Since the goal is to produce at least 2 quarts of urine a day, you should drink more fluid in very hot weather to make up for that lost by sweating.

A good way to judge whether you're drinking enough is to watch the color of your urine. If your urine is dark and yellow, drink more. It should be pale, almost watery. Urine has more color in the morning when it is most concentrated, but the rest of the time, the less color the better.

Drinking plenty of fluids also reduces the risk of urinary tract infections - a major cause of struvite stones. Any infections that do occur should be treated promptly and completely.

Depending on the kind of stone involved and the results of laboratory tests, your doctor may advise you to eat less of certain kinds of foods. For example, patients with calcium oxalate or uric acid stones may need to reduce the amount of meat products and table salt in their diets and increase the amount of fiber. You and your physician may work with a dietitian to develop a diet suited to your particular needs.

There are prescription medications that help some patients. Diuretics, such as hydrochlorothiazide, decrease calcium excretion. Potassium citrate binds calcium and helps to remove it safely. Allopurinol, which causes the body to produce less uric acid, is sometimes prescribed for patients with gout. It also reduces their risk of forming uric acid or calcium oxalate stones. Patients taking medications still need to drink at least ten 8-ounce glasses of fluid per day. When cystine stone formation can't be controlled by increased fluid levels alone, penicillamine or tiopronin may be prescribed to make it easier for the body to dissolve cystine. Other specific medications may be prescribed by your doctor.

Feel free to discuss these and any other questions you have with your doctor.

Remember, the single most important way to help prevent kidney stone formation is to stay well-hydrated.


How long does the procedure take?

You will be asked to arrive approximately 1 hour before your scheduled treatment in order to complete paperwork, be interviewed by nurses and anesthesiologist, and possibly to receive pre-procedure medication and/or hydration. Your total time at the facility will be approximately 3 to 4 hours, including 1 hour for the actual treatment.


When can I go back to work?

Most people can return to work 2-3 days after the procedure. However, it is very individualized depending on the procedure that your doctor performs.


When can I resume sexual relations?

Within a couple of days, unless your doctor leaves a string attached to the stent. In that case, you must wait until the stent is removed.


What can a patient expect during a Lithotripsy treatment?

Treatment is fairly simple and typically proceeds in the following manner:

Hospital personnel will bring you to the treatment unit.

The patient will be comfortably positioned on the treatment table.

An x-ray will be taken to determine the precise location of the stone(s).

The shock wave applicator will be placed against the side of the body.

The applicator will direct a series of wave impulses which pass harmlessly through your body. These impulses are absorbed by the stone, causing it to fragment.

The lithotripter includes video x-ray equipment enabling the physician to see stones, follow the fragmentation process, and carefully monitor the entire treatment procedure.

Following treatment, you will be taken to a recovery area to be observed for a short period of time.


Why do I need a driver?

You will receive some form of anesthesia for the procedure. Anesthesia may include narcotics and sedatives, making driving dangerous to you and others.


What is a stent?

The stent is a sterile hollow flexible tube that the physician places into the kidney drainage system. This allows the kidney to drain around the pieces of stone. It also continues to drain the kidney as you pass the stone fragments created by the lithotripsy procedure.


Who determines if I need a stent?

Your doctor makes that decision based on stone size, location and other symptoms i.e. pain or infection.


How does the doctor put in the stent?

Your doctor uses a special instrument called a cystoscope to look into the bladder through the urinary opening. Once the scope is inside, he/she locates the opening to the ureter ( kidney drainage tube) and slides the stent into the kidney.


How long will the stent be in?

The stent needs to stay in until the majority of the stone fragments have been passed, which can be approximately one to two weeks.


How do I know if I'm dehydrated?

Thirst is the last indicator that you are low on fluids. Once you are thirsty, you are already dehydrated. If you void infrequently and /or the urine is a dark yellow to amber color, the urine is concentrated. This means you are dehydrated. A good rule is to drink 8 ounces of water every time you void replacing water that you have just lost. If you consume coffee, tea and colas you increase your chances of being dehydrated because caffeine is a diuretic.


My friend says that I should drink a lot of cranberry juice, is that true?

Cranberry juice is excreted as an acid. This makes it beneficial in cases where a person has frequent bladder infections by keeping down bacteria growth. However, for some stone formers, it can encourage stone growth. If the urinary tract is irritated by a stone or by a stent or other procedure, cranberry juice will irritate the system even more.