By Sameer Deshmukh, MD
Most of us are familiar with kidney stones and the pain they can cause. Your chances of developing a stone in your lifetime are one in 10. And once you’ve had one kidney stone, your odds of developing another one increase by 50 percent.
Kidney stones are caused when concentrated minerals like calcium, oxalate, and uric acid in your urine form into crystals. “Passing” a kidney stone or stones (yes, there can be more than one at a time) occurs when these hardened crystals move from your kidneys into your urinary tract and bladder (over days, weeks, or months) and are then excreted in your urine.
The good news? Kidney stones rarely cause permanent damage, and, depending on your situation, medication and lots of water may be all that’s needed to pass them. Even better news is that prevention with proper hydration and diet and maintaining a healthy weight can dramatically reduce your risk of developing kidney stones or a recurrence.
You may not feel the kidney stone until it enters your ureter (the thin tube connecting each kidney to your bladder). Once there, though, the pain a stone can cause is legendary. You may experience severe, fluctuating pain in your side and back that radiates to your lower abdomen and groin. Some people experience pain while urinating and feel an increased need to urinate. Another symptom is foul-smelling, pink, red, or brown urine. Infection is possible, as well, causing fever and chills.
Seek immediate medical attention if you are vomiting and/or have a fever. If your pain is less intense but consistent (or increasing), see your doctor as soon as possible. If the stone does not pass out of your system on its own, you will need treatment by a urologist.
The most common treatment is ureteroscopy with laser lithotripsy, followed by Shock Wave Lithotripsy (SWL). With ureteroscopy, which requires anesthesia, the doctor inserts a small, flexible telescope into the bladder and ureter and pulls the stone free with a tiny wire basket. This outpatient, minimally invasive procedure is effective for stones of varying sizes. Holmium laser treatment also may be used with a small ureteroscope to “crush” the stone into smaller pieces before removing it. Any smaller, dust-like particles pass through the urine.
With SWL, which also does not require an incision, the doctor positions you on an operating table and uses 1,000 to 2,000 shock (pressure) waves delivered outside the body to target the stone and break it into fragments small enough to pass through your urinary tract. The outpatient procedure requires anesthesia (either light sedation or local or general anesthesia) and is usually completed within about an hour.
Your doctor may recommend another treatment method depending on your stone’s location and size, your kidneys’ health and your overall health. Those who are pregnant, morbidly obese, have a bleeding disorder, infection, skeletal abnormalities, or cardiac pacemaker are not good SWL candidates.
If surgery is needed, today’s surgical treatments are less invasive than ever before. A decade ago, kidney stone surgery usually required a traditional procedure with a large incision, several days in the hospital, and a longer recovery. Now, urologists can perform mini- or micro-percutaneous nephrolithotomy (PCNL). First introduced in pediatric patients, this outpatient surgery uses a miniature endoscope via a small percutaneous tract to remove stones, even large stones, in different locations.
Rarely is there a definite cause of kidney stones, but there are well-known risk factors, with obesity and diabetes topping the list. Genetics play a role, too, as can certain diseases, such as inflammatory bowel disease and chronic diarrhea, which may increase the levels of substances in your urine that cause crystals to form.
Hydration is the most important step to take to decrease your risk of developing kidney stones or having a recurrence. Drink enough water each day to produce about 2.5 liters of clear urine. Cloudy, dark urine is a sign that you are not drinking enough water. Though water is best, other liquids such as citrus drinks may also help prevent kidney stones. Some studies show that citrus drinks, such as lemonade and orange juice, protect against kidney stones because they contain citrate, which stops crystals from turning into stones. Avoid soda. Research indicates that sugar-sweetened and artificially sweetened sodas may increase the risk of kidney stone formation.
What you eat also counts. Avoid diets high in protein, refined carbohydrates, and sugar, and watch your salt intake. Too much salt makes more calcium for your kidneys to filter, creating a perfect environment for stones to form.
If you have passed a stone and want to prevent a recurrence, try to save your stone. Your doctor can analyze it for clues as to what kind of kidney stone you had, and how best to prevent future stones.
For detailed information on kidney stones, visit MAPMG’s Staying Healthy pages.
Sameer Deshmukh, MD, is a board-certified urologist with Mid-Atlantic Permanente Medical Group. He sees patients at the Kaiser Permanente Fair Oaks Medical Center in Fairfax, Virginia.