When Yolanda Alonso, 49, of El Escorial-Madrid, first felt the twinge in her right side, she assumed she was ovulating. Over the next couple of days, though, the pain escalated, reminding her of the excruciating contractions she suffered when giving birth to her now teenaged daughter.
But labor pains wax and wane. These were unrelenting.
Soon, Yolanda could barely function. Frightened, she had her husband take her to the nearest hospital emergency department. After X-rays and other tests, doctors returned their diagnosis: She had a kidney stone.
Yolanda was given intravenous painkillers and sent home with oral ones to take while she waited for the kidney stone to work its way out of her system. The pills helped for a few days “until I had another severe attack, and I went back to hospital and had intravenous medication again.”
Finally, her agony abruptly ended. The stone passed on its own.
Kidney stones are probably the most painful condition known. Considering their tiny size—typically just a couple of millimeters (about half the length of a grain of rice)—it’s surprising that they can cause such debilitating symptoms. And for so many of us.
“One out of ten [people] will develop a stone,” says Professor Thomas Knoll, a urologist with the University of Heidelberg. If you look at Europe, for example, that adds up to about 55 million potential kidney stone sufferers. And the incidence has been rapidly increasing—it has doubled in the past 30 years, says the European Association of Urology. Considering their prevalence, it’s important to be informed.
How the stones form
Various substances circulate through your body all the time; any excess is sent to the kidneys for disposal. The more urine you produce, the more likely your body is to flush away this excess. But when minerals and other substances clump together before they can be expelled, kidney stones can form.
The typical kidney stone is a combination of calcium and an organic acid called oxalate. The second most typical stone develops from uric acid, the culprit in gout (not surprisingly, gout predisposes people to produce kidney stones). Calcium also can combine with phosphate to form stones. And other minerals are responsible in people with a genetic propensity towards kidney stones.
A stone usually only makes itself felt after it leaves the kidney. If it gets stuck in the ureter (through which urine moves from the kidney and bladder) and blocks the flow of urine, the pain can be extreme. It’s the body’s unsuccessful attempts to push through the blockage that cause the pain.
To confirm that pain is due to a kidney stone, doctors first use X-rays and sometimes CT scans (helpful for detecting tiny stones). Blood and urine analysis can show whether greater than normal levels of stone-forming substances are circulating through your system.
What causes them?
Dehydration is a major risk factor. “If people don’t drink enough, they have a higher risk of stone formation” says Professor Knoll. (These are the signs you’re not drinking enough water.) But with more and more people developing stones, it can’t be all chalked up to low fluid intake. Instead, blame it on the good life. As we grow in bulk, becoming a more overweight population, we also grow more prone to kidney stones. And it’s not just how much we eat, but what we eat.
“A diet that is rich in meat, primarily red meat, contributes to the stone formation risk,” says Dr. Hendrik Heers, a urologist at Oxford University Hospitals in the U.K. “Vegetarian patients have a much lower risk of kidney stones compared to the meat-eating population.” (These are the best plant-based sources of protein.)
A diet heavily reliant on processed food, such as canned, frozen and other packaged fare, can also increase the risk of stone problems, says the U.S.’s National Institute of Diabetes and Digestive and Kidney Diseases. Processed foods tend to be high in sodium (salt), and excess salt increases the amount of calcium you excrete in your urine.
And, while kidney stones are most often a problem for the middle-aged and older, according to a 2012 study children too, especially adolescents, are susceptible. Alarmingly, the incidence of kidney stones in those younger than 18 has increased dramatically in the past 25 years. “That is absolutely, from my point of view, related to the diet,” says Dr Palle J.S. Osther, Professor of Urology at Lillebaelt Hospital in Fredericia, Denmark.
No one is immune
When she was just 18, Rushka Robert was stunned by a sudden agonizing pain in her right side. Writhing and vomiting, the young Amsterdam native barely managed to make it to her bed. Her mother, a former nurse, assumed appendicitis. When they called their GP, however, he immediately suspected kidney stones. The ambulance crew gave Rushka a fast-acting shot of painkillers, and at the hospital her GP’s diagnosis was confirmed.
The next day, after more painkillers, Rushka was sent home to wait for the stone to pass.
But it didn’t. The pain worsened. She couldn’t urinate at all. She’d never known such torment.
Back in hospital, Rushka was told that they had to operate. Surgery was successful—but that wasn’t to be the end of Rushka’s battle.
How to prevent a second bout
If you’ve suffered one bout with kidney stones, you have as high as a 50 percent chance of having another. “And you have about a 20 percent risk of having three or more stone episodes,” says Dr. Heers.
But new problems can often be prevented with a few simple lifestyle changes. “Drink a lot to reduce the risk of getting a new stone,” says Professor Osther. Aim for two liters of urine production a day, he says. To hit that target, you should drink at least two and a half liters. “And when the weather’s warm, you should drink even more.” Those with a genetic propensity to form stones should double those amounts.
Although water is an obvious choice, other fluids might be even more effective. Coffee drinkers tend to have lower risks of kidney stones. But citrus juices take the prize, says Professor Knoll, especially lemon and grapefruit. “They elevate the PH level of the urine,” he says. In other words, citrus makes your urine more alkaline, in which case “you reduce the risk of almost all stone formation.”
Avoid citrus drinks with sugar though, as the sweetener can increase your risk, undoing the good the juice by itself does.
Depending on the chemical make-up of kidney stones, your doctor might advise you to limit certain foods. Meat and eggs are high on the list, as is shellfish, but plant-based foods with a high oxalate content such as peanuts, rhubarb, spinach, beetroot, chocolate and sweet potatoes can also cause problems for some.
Sometimes, however, changing your diet just isn’t enough. For those with uric acid stones, a gout medication called allopurinol is often prescribed to reduce their incidence.
Diuretics in the thiazide family (hydrochlorothiazide, chlorthalidone, and indapamide) can reduce the amount of calcium excreted by the kidneys and help prevent calcium-based stones.
But for some, like Rushka, prevention is not so straightforward. Just two years after her surgery for her first kidney stone, she suffered many of the same symptoms again. This time, she was completely disheartened.
She had done everything her doctors had recommended: cut back on dairy and sugar, even stopped eating spinach altogether. Yet x-rays showed almost two dozen stones sitting in her kidneys.
Although she was able to avert another surgery, Rushka suffered three more stone-related ordeals before a new doctor offered the most promising preventive medication: potassium citrate pills.
Now 26, Rushka Robert is taking 12 potassium citrate pills a day. And it’s worth every swallow. “After six months, a new count showed just two stones on the left and one on the right,” she says. She’s hopeful that the medication will keep her stone-free.
As Rushka, or anyone who’s been through kidney stone hell will tell you, it’s worth almost anything to prevent another bout.
How are kidney stones treated?
Until recently, medications that treat high blood pressure (nifedipine) and enlarged prostate (tamsulosin) were routinely given to hurry the expulsion of stones. But a large study published in July 2015 showed that these medications are no better than placebo at speeding passage. The new thinking is to treat only for pain while waiting for stones to make their own way out. Of course, not all do.
“The bigger the stone, the more unlikely is a spontaneous passage,” says Dr Heers. Occasionally, even a small stone will get stuck in the ureter. Surgery is then the answer, but it’s almost always minimally invasive.
The three most common types of surgical treatment are:
Shockwave lithotripsy: Sound waves are focused on the stone from outside the body, breaking it into smaller pieces that can be passed in the urine. Pros: Least invasive. Usually an outpatient procedure. Cons: If the stone has a very hard composition more than one treatment is often needed.
Ureteroscopy: A small tube is inserted into the urinary tract and the stone is either pulled out or a laser is used to break it up. Pros: Most successful method for removing small to medium stones. Often an outpatient procedure. Cons: There is a slight risk of damage to the ureter. Sometimes a catheter must be left in place until the stone passes.
Percutaneous Nephrolithotripsy: A small incision is made in the back directly into the kidney so that stones can be accessed and removed. Pros: Most successful method for removing larger stones. Cons: More invasive than the alternatives, requires a hospital stay and longer recovery time.