Tuesday, October 26, 2010

Kidney Stones

Kidney stones are abnormal, hard, chemical deposits that form inside the kidneys. This condition also is called nephrolithiasis or urolithiasis.

Kidney stones are often as small as grains of sand and pass out of the body in urine without causing discomfort. The deposits can be the size of a pea, a marble or even larger. Some of these larger stones are too big to be flushed from the kidney. Others manage to travel into the narrow tube between the kidney and bladder (ureter), where they become trapped. Trapped kidney stones can cause many different symptoms, including extreme pain, blocked urine flow and bleeding from the walls of the urinary tract


Very small kidney stones may pass out of the body in the urine without causing symptoms. Larger stones may become trapped in the narrow ureter, causing severe pain in the back or side, nausea and vomiting, or blood in the urine. If there is blood in your urine, the urine may look pink, red, or brown. If the location of pain shifts downward, closer to the groin, this usually indicates that the stone has traveled downward in the ureter and is now closer to the bladder. As the stone approaches the bladder, you may feel a stronger urge to urinate or a burning sensation when urinating. When stones pass out of your body in your urine, you may see the stones exit.


In general, you can help to prevent kidney stones by drinking plenty of fluids and avoiding dehydration. This dilutes your urine and decreases the chance that chemicals will combine to form stones.

You can prevent calcium oxalate stones by eating low-fat dairy products and other calcium-rich foods. Taking calcium supplements, however, can increase the risk of stone formation. Calcium in your diet binds oxalate inside the intestines to decrease the amount of oxalate that gets into the blood, so less spills in the urine. People who excrete too much oxalate into their urine should avoid eating foods high in oxalate, including beets, spinach, chard and rhubarb. Tea, coffee, cola, chocolate and nuts also contain oxalate, but these can be used in moderation. Eating too much salt and meat can cause more kidney stones to form.

After doctor receives an analysis of the chemical composition of your kidney stones, he or she can suggest medications or changes in your diet that will help to prevent stones from forming in the future. Because certain medications may increase the risk of stones, your doctor may want to adjust your regular medications if you have had kidney stones.


In many cases, a trapped kidney stone eventually flushes out of the urinary tract on its own, especially if you drink plenty of fluids. With a doctor's supervision, it is likely that you can remain at home, taking pain medicine as needed until the stone dislodges and flushes away. If the stone is too large to pass on its own, if your pain is severe, or if you have infection or significant bleeding, it may be necessary for you to have your stone removed or broken into fragments that can pass more easily. Doctors have several options for destroying stones lodged in the urinary tract:

Extracorporeal lithotripsy

Shock waves applied externally break kidney stones into smaller fragments, which are then swept away in the urine stream.

Percutaneous ultrasonic lithotripsy

A narrow tubelike instrument is passed through a small incision in the back to the kidney, where ultrasound breaks up the kidney stones. The stone fragments are then removed.

Laser lithotripsy 

A laser breaks up stones in the ureter. The stones then pass on their own.


A very small telescope is inserted into the ureter and guided to the bladder. The stone is then either fragmented or removed.

It is rare that surgery is required to remove a kidney stone.

No comments:

Post a Comment