Kidney Stones

What Are Kidney Stones?

Just as the name implies, these are small calcifications or stones that form in the urinary tract.  Usually stones form in the kidney but they may also start in the bladder.  Estimates are that as many as 10% of people will have a stone at some point in their life.

What Are Kidney Stones Made Of?

Many different substances can crystallize in the urine to form a stone.  About 80% or 85% of the stones in the U.S. are made of calcium oxalate or calcium phosphate.  Another 10% or so are made of uric acid.  The remaining small percentage of stones are made of cystine, struvite or other, less common, substances.

What Causes Kidney Stones?

There are many reasons for people to form kidney stones.  Probably the most common reason is lack of fluid intake leading to concentrated urine in which stone crystals can form.  Diet is sometimes an issue especially for people who eat a lot of salt or foods containing oxalate.  Sometimes it is a matter of how the kidney filters extra calcium from the blood.  Less common, are medical problems which cause too much acid in the urine or overproduction of calcium, uric acid, etc.  Some medications can cause stones.

How Do I Know if I Have a Kidney Stone?

The most common or classic sign of a kidney stone is the sudden onset of severe pain in the flank on one side or the other.  The pain is often severe enough that it also causes nausea and vomiting and may move to the lower abdomen or groin.  These symptoms occur when the stone is trying to pass through the narrow channel that carries urine from the kidney to the bladder.  Some people also notice blood in the urine when they are passing a stone.  An x-ray or CT scan will reveal the presence and location of the stone.  Stones can, however, sit in the kidney without moving and cause no problems at all.

How are Stones Treated?

By far, the best approach is to control the symptoms and allow the stone to pass on its own.  If, however, the pain cannot be controlled or the stone gets stuck somewhere in the system there are a number of options:
1.  Medications like tamsulosin may help stones pass on their own.

2.  Lithotripsy is a noninvasive way of treating stones using shockwaves which pass harmlessly through the skin and break the stone into tiny pieces which then usually pass with a minimum of difficulty.

3.  Ureteroscopy involves threading a tiny scope into the urinary tract and using a laser to fragment the stone.

4.  Percutaneous procedures involve inserting a tube through the skin into the kidney and using a laser or ultrasound to fragment the stone.  This is usually reserved for larger stones that are stuck in the kidney.
5.  Sometimes uric acid stones can be dissolved using medicines that reduce the acidity of the urine.
 

I Have Had Kidney Stones, How Can I Prevent More?

There are many approaches to preventing kidney stones.  Before deciding what to do, it is important to know why a person is forming stones.  Therefore, we often need to do some special blood and urine studies to find out.  Depending upon the results, medicines, dietary changes, lifestyle changes, etc. may be necessary.

There are, however, some things that are almost always helpful:
1.  Drink lots of water and citrus juices (real lemonade, real limeade, grapefruit, etc.).  You should drink enough that you produce at least 2 quarts of urine every day.
2.  Avoid excess caffeine intake.
3.  Avoid excess salt intake (more than 2 g of sodium daily).
4.  Maintain a moderate intake of foods high in oxalate (Google “oxalate–containing foods” for a list).

We hope that this answers some of your questions about kidney stones.  Call Gallatin Urology (406–551–2306) for an appointment if you need more information or if you are having problems with stones!