While you’ve likely heard of kidney stones (and the pain they can cause), there’s a lot of misconceptions about these pebble-like deposits.
Kidney stones are hard formations that develop in your kidneys when there is a high concentration of substances like calcium, oxalate, uric acid and phosphorus in your urine. They can vary in color, density, location and shape, and range in size from as small as a grain of sand to, in rare cases, as large as a “spikey” golf ball.
Perhaps the most common misconception is that kidney stones only happen to men, but this is simply not true. Around 11% of men and 6% of women are diagnosed with kidney stones in their lifetime, and this gender gap is closing as women are diagnosed at increasing rates.
While some of this is likely due to improved sensitivity of imaging — even tiny, symptom-free stones can be seen with today’s advanced technology — much of the increase can likely be attributed to common health-related challenges: our ongoing obesity epidemic and the health challenges posed by our diets and sedentary lifestyles.
How kidney stones affect women
While women’s overall lifetime risk is lower than men’s, obesity, diabetes and associated metabolic syndromes have narrowed the gap, according to Dr. Robert Sweet, medical director of the Kidney Stone Center at UW Medical Center – Northwest.
Plus, a recent epidemiological study spanning decades demonstrates that people who develop symptoms from kidney stones tend to be female, with the highest increase in incident rates between women ages 18 to 39. Women also had a higher frequency of infected stones as a result of recurrent urinary tract infections (UTIs).
“Women’s risk of getting stones is greater than for men if they are obese,” says Sweet. “When women who have these other conditions have a kidney stone, they are also more likely to have complex stones that are more difficult to treat and have accompanying urinary tract infections and pain that reduces quality of life.”
Climate change as a risk factor
Besides metabolic conditions increasing kidney stone risk, there’s another component that may increase the risk over time for the whole population: climate change. Researchers have long noted a correlation between kidney stone rates and temperature, notes Sweet.
“Here in the U.S., we call it the Stone Belt: hotter, drier climates in the Southeast and South show a higher prevalence of stones and stone patients. We already know heat is a risk factor, as well as fluid intake,” he says.
If you are extremely active and not replenishing fluids in hot, dry weather, that can also increase your risk of developing kidney stones.
Kidney stone symptoms: Pain, pain and more pain
While some small kidney stones can pass through the urinary tract and out of your body without being noticed, others have tell-tale signs, most notably: pain.
Symptoms are similar regardless of gender, and include pain in your back or sides, radiating pain into the groin, nausea, vomiting, blood in the urine and fever. The presence of stones in the kidney can also lead to chronic UTIs, so if this is something in your own history, it’s a good idea to bring it up to your doctor.
Kidney stone treatment options
The key to treating kidney stones is to get the right diagnosis through imaging to see the size and location of the stone.
“The pain really comes from the stone blocking the collecting system within the kidney so urine can’t get by. The obstruction causes the pain. So, to treat this, we work to reduce the pressure in the kidney,” says Sweet.
The first course of action is usually to treat the pain and reduce inflammation using medications to see if the stone will break down and pass on its own. If a stone won’t pass, further treatment can reduce the pressure inside the kidney and reduce the risk of infection.
Medical expulsion therapy
For some stones that are under 1 centimeter and are in the ureter, a tube that carries urine from the kidneys to the bladder, you can choose a trial of medical expulsion therapy. In the trial, medicine is taken to relax the smooth muscle in the ureter and facilitate passage of the stone into the bladder.
Note that if you’re pregnant, imaging, treatment and pain management options must be carefully weighed for risks and benefits. Occasionally a complication called hypercalcemia of pregnancy can occur and cause stones.
Shock wave lithotripsy
This treatment is a good option when you only have one or two stones that are softer and not in a dependent location. You are given general anesthesia and doctors target the stone with high-energy sound waves to crack and break up stones into small enough pieces to pass. Since this is done from outside the body, no incisions are made.
The procedure is low risk but less precise and relies on you to pass the debris on your own. In most cases, you are able to go home the same day as the procedure.
This is the most common surgical approach for stones. You are given general anesthesia and doctors insert a small instrument into the urinary tract (urethra). No incisions are needed. Instead, doctors simply guide the instrument to the stone.
A laser beam is then passed through the scope and breaks up the stones into smaller fragments that can either be removed or flushed out through the ureter. Multiple stones in difficult locations can be managed in this way, and you are typically able to go home the same day.
In these procedures, the doctor makes a small incision, about 1 centimeter, in the back to insert a camera, fragmentation/vacuum and retrieval devices into the kidney.
This is the preferred option for big, complex or irregularly shaped stones, as doctors can elect to approach the kidney from multiple directions, which reduces the number of treatments needed over time. Typically, you are discharged from the hospital in less than 24 hours after this procedure.
And with any of these treatment options, a small drainage tube may be left after the procedure. This tube is a temporary way to allow the urinary tract to heal and is later removed by you or your doctor.
Once you have had a stone, your chances of having another is higher. So how can you prevent others from forming?
Sustainable, long-term dietary and lifestyle changes are the tried-and-true solution for reducing your risk of recurrence. At UW Medicine, you can work closely with on-staff dieticians to determine a personalized plan that will fit your life.
“People will do anything to not have a stone again, but extreme responses won’t be sustainable,” adds Sweet.
Helpful changes to prevent additional stones include increased fluid intake, reducing sodium to 2,300 milligrams per day or less, increasing citric acid in the diet and focusing on fruits and veggies over animal proteins.
“We work closely with patients to make sure things will really work for them over the long term,” says Sweet. “We really see ourselves as a partner and a resource because of our multidisciplinary approach.”