What is a kidney stone?
A kidney stone is a rock or particle crystal in the urinary tract formed by
substances in urine.
- Kidney stones affect 10% of men and 5% of women aged 30-50. Children and
teenagers also get kidney stones.
- They vary in size from a grain of sand to the size of a tennis ball.
Regardless of the size, they are one of the most painful medical problems
- Kidney stones can cause permanent damage to the kidneys if not treated
- Recurrence is common. Men have a 67% recurrence rate.
What causes a kidney stone?
No one really knows. The most common theory is called supersaturation
crystallization. In this theory, dehydration causes calcium phosphates,
oxalates, urea, uric acids, citrates, complex mucoproteins or other trace
elements in urine to combine and crystallize.
- Some studies show that dehydration increases the chances of having stones.
Drinking plenty of water may prevent kidney stones. People living in the
southeastern U.S. have more kidney stones than people living elsewhere, and it
is thought that the cause may be related to temperature and dehydration.
- Studies have been conflicting on the relationship of minerals in water to
kidney stones. Some studies show hard water (water with excessive calcium
sulfate) contributes to kidney stone formation, while other studies show soft
water (with excessive sodium carbonate) contributes to a greater incidence of
stone disease. Yet other studies demonstrate that trace elements in water may
be the culprit.
- A high fat diet seems to be related to kidney stones. Eating a high
protein diet, dark green leafy vegetables, tea, and chocolate may increase the
chance of forming kidney stones.
- Kidney stones tend to run in families.
Symptoms of a kidney stone
Kidney stones are very common and dangerous. If kidney stones are not treated
properly, permanent kidney damage can result.
- A typical stone attack is a sudden pain occurring at night or in the early
morning. The pain starts in the loin and radiates around the abdomen down into
- Nausea and vomiting are common. Often you cannot sit or lie still.
- Kidney stones are often confused with other diseases such as acute
appendicitis, gastroenteritis, colitis and other bowel disorders. Occasionally
those complaining of back pain for months, or even years, are found to have
large kidney stones.
What to expect if a stone is suspected
- Because most kidney stones cause blood in the urine, the first test
usually performed is a urinalysis and then a simple x-ray of the abdomen is
taken to find the stone.
- An intravenous pyelogram (IVP)is often needed. In this procedure, a small
amount of dye is injected through a vein, and x-rays are taken to find out
exactly where the stone is and how big it is.
- Sometimes an ultrasound is used instead of an IVP, especially to avoid
allergic dye reactions.
- In rare cases, a computed tomography (CAT) scan is necessary.
- If kidney stones begin to recur, a metabolic stone evaluation of urine and
blood samples should be done to see if an underlying cause can be found.
Six different treatment options
1. Extracorporeal shock wave lithotripsy
Shock wave lithotripsy is often used to treat kidney stones. It is one of the
most important technological advances in kidney stone treatment. It has a
success rate of 98%.
All lithotripters are not alike. There is a
new lithotripter that is dramatically better than others. Older machines use
technology that's about 20 years old. They require a substantial amount of
anesthesia, more x-rays, and a water bath. Not only does the new lithotripter
allow you to skip the water bath, and probably the anesthesia, it treats more
types of kidney stones (including those especially painful ones in the ureter)
and can cut treatment time in half!
- In shock wave lithotripsy, a machine called a lithotripter is used to
generate a shock wave outside of the body. The shock wave is focused on the
kidney stone, which breaks into tiny pieces and passes painlessly. This is an
- The more advanced lithotripters do not require general anesthesia or water
baths. In addition, they can treat stones in the ureter, avoiding
||The Kidney Stone Center in Bloomington, Indiana, is one of the few
places in the country that offers the new, advanced lithotripter, the Doli50
manufactured by the Dornier Corporation. Treatment by these new lithotripters
is dramatically different than by the old types of machines. Be sure to find
a new Doli50 lithotripter for your next kidney stone treatment.
Used for stones in the lower ureter, this treatment has a 95% success rate.
- Ureteroscopy can be done as an outpatient procedure under anesthesia.
- A small telescope is passed through the bladder to the stone. The stone is
removed using a small basket or is broken up using a very small shock wave
- Following the procedure, a small silicone tube is left inside the ureter
for 5-7 days to help relieve swelling.
3. Percutaneous nephrostolithotomy
If a kidney stone is larger than 3 centimeters (over 1 inch), a percutaneous
nephrostolithotomy is often used for treatment.
- Instruments are passed through a small tract passing through the side of a
patient into the kidney to break up the kidney stone.
- This procedure requires general anesthesia and hospitalization.
4. Electrohydraulic lithotriptor
This procedure uses shockwaves produced by a small internal probe to break up
- Commonly used for small kidney stones.
- Requires general anesthesia.
5. Open stone surgery
Rarely used anymore, this procedure requires a large incision and prolonged
Some kidney stones do not cause any pain. If small, they will pass on their
own. Larger stones get stuck in narrow parts of the kidney and ureter, causing
The best treatment for small, non-painful kidney stones usually is to allow
them to pass on their own. An x-ray 1-2 weeks after discovery helps track how
the stone is progressing.