The only thing worse than the agonizing pain of a kidney stone: knowing that when you’ve had one, there’s a 50 percent chance you’ll have another.
To improve those odds, University of Minnesota Health physicians have created the innovative, multidisciplinary Kidney Stone Program. Urologist Michael Borofsky, MD specializes in treating kidney stones. We asked Borofsky for help answering some basic questions about this surprisingly common ailment.
Kidney stone disease is an incredibly common condition that affects nearly 10 percent of people in the United States—and that rate is rising rapidly. Kidney stones themselves are not actually stones. Instead, they are large collections of crystals that have joined together to form a solid structure. Stones form in urine, which contains minerals and other substances. Normally, these minerals leave our body through urination before stones can develop. However, when urine contains high levels of crystal-forming substances, kidney stones can become a problem. In some cases, small stones pass without symptoms. Larger stones are problematic because they can become stuck in the urinary tract when trying to pass. They may also grow to the point that they can cause other symptoms, including pain, infections, and kidney damage.
The most common warning sign of a kidney stone is pain in the flank or lower back on one side of the body. Sometimes, this may be accompanied by visible blood in the urine or nausea and vomiting. On occasion, a care provider will discover a kidney stones during the treatment of recurrent urinary tract infections, or on unrelated medical imaging being done to treat another condition.
The most important part of kidney stone prevention is proper hydration. Adequate hydration will minimize crystal formation in the urine. We recommend that you consume three liters or more of fluid. Other preventative strategies may depend on the type of stone that is formed. Most stones are made of calcium but other, less common stones can be made of uric acid, struvite and cystine. To maximize the effectiveness of treatment, we try to identify the reasons why a particular stone formed in the patient. Once we have a better understanding, we may prescribe other treatments, including dietary changes such as minimizing salt intake or avoiding foods high in oxalate. In other cases medications may be necessary.
Major surgery to remove stones is almost never necessary. When stones are small (5 millimeters or less), they often are capable of passing on their own. In such situations, medications may be used to relax the urinary tract and increase the chances of successful passage. Other medications can keep pain under control during this process, which can take several days to several weeks.
If the stone is not making progress or is unlikely to pass on its own, we may treat it by using an instrument called a ureteroscope to break the stone into pieces or remove it altogether.
Shock Wave Lithotripsy (SWL) is another common, noninvasive treatment. During SWL, a care provider will use a machine to focus waves of energy on the stone from outside of the body with the intention of cracking the stone into smaller fragments. Finally, the largest and most complex kidney stones may be best treated by a procedure called a percutaneous nephrolithotomy. With this approach, a small incision is made in the back and a telescope is passed directly into the kidney. Once the stone is identified it can then be directly fragmented and removed.